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Guitar Music Theory
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Guitar Music Theory.md

Table of Contents

Strings

Let's start by learning the strings of the guitar.

There are 6 strings on most traditional guitars †

† there are also 7 and 8 string guitars nowadays too

For 6 string guitars you'll have three 'bass' strings and three 'treble' strings.

Bass strings have a lower sound, and treble strings provide a higher pitch/sound.

The strings are numbered 1 to 6 (1 being the highest sounding note and 6 being the lowest sounding note).

The strings have letters associated with them to indicate the particular note they're tuned to.

So in a 'standard tuning' the guitar strings would be (counting backwards):

    1. E (the low E string)
    1. A
    1. D
    1. G
    1. B
    1. E (the high E string)

The best way to remember this is to assign a mnemonic such as:

  • (E)lephants
  • (A)nd
  • (D)ragons
  • (G)row
  • (B)ig
  • (E)ars

The above example mnemonic always worked for me, but feel free to choose one that works best for you.

Before we move on, you just need to know that when discussing the frets on the guitar's fretboard (the 'fret' refers to each of the metal bars that are placed across the guitar's neck underneath the strings), the fret nearest the top of the guitar is the first fret, followed by the second fret and the third fret and onwards.

Note: some guitars have more 'frets' than other guitars

OK, now we know the strings of the guitar we'll just jump straight into understanding the guitar's fretboard...

Fretboard

To understand the fretboard you need to know that in music there are twelve 'pitches'.

Each one a semi-tone above or below the another.

Here are those 12 tones:

A, A♯, B, C, C♯, D, D♯, E, F, F♯, G, G♯

The first thing to notice is that the complete musical range is really just the first 7 letters of the alphabet.

That's easy to memorise :-)

The next thing to notice is that B and E are the only notes that have no sharp ♯.

OK, that's easy to memorise as well.

With that out of the way, let's get an overview of the fretboard...

Frets > 1 2 3 4 5 6 7 8 9 10 11 12
1 (E) F F♯ G G♯ A A♯ B C C♯ D D♯ E
2 (B) C C♯ D D♯ E F F♯ G G♯ A A♯ B
3 (G) G♯ A A♯ B C C♯ D D♯ E F F♯ G
4 (D) D♯ E F F♯ G G♯ A A♯ B C C♯ D
5 (A) A♯ B C C♯ D D♯ E F F♯ G G♯ A
6 (E) F F♯ G G♯ A A♯ B C C♯ D D♯ E

I found the best way to learn the fretboard is to find a pattern.

Note: print out the above 'overview', grab a pen and look for patterns like you would use a wordsearch

The pattern I used was to learn the notes on the top two strings (the low E and low A strings) and to assign mnemonics to them. This made it easier for me to identify them and then this led me onto discovering that these same adjacent notes also appeared across the fretboard (making it easier for me to figure out where notes appear).

For example:

  • F|A♯: I think of the FA cup (a football association)
  • F♯|B: I think of Facebook
  • G|C: I think of Garbage Collection (as in the programming concept)
  • A|D: I think of After Death (as in Anno Domini)
  • B|E: As this is just an English word ("be"), I always remember B to be followed by an E
  • C|F: I think of Cloud Formation (a programming related term)
  • D|G: I think of Director General
  • E|A: I think of the game company EA Sports †

You might wonder why I don't think of mnemonics for notes such as found on the 4th fret (G♯|C♯)? That's because I don't need to. I know the next note up from G will be G♯ and so I know on the next adjacent string the C will subsequently become C♯.

Now, the above mnemonics won't work for you. They work for me because they make sense to me. You need to choose something that makes the most sense for you. A few days of just looking at your guitar randomly throughout the day and identifying the notes on the top two bass strings (or if you're at work: just grabbing a pen and paper and writing down the notes) and you'll have them memorised.

† a moment ago I said...

"I think of the game company EA Sports"

...this actually led me to realise, that at the 12th fret the notes would match the name of the strings. These notes were an 'octave' higher than the open string notes (e.g. play the strings without any frets pressed down and you'll hear the 'open' notes).

From here I would realised there was a pattern I could use:

the notes of the top two bass strings would appear in that order across the fretboard!

Let's put this into practice...

If we look at the 5th fret we see an A.

OK, but now can you guess the note on the next string along at the 5th fret?

Well if we've memorised the top two bass strings then yes, we'll know it is a D.

From there I noticed the note on the next string along after that (we're still at the 5th fret for this example) was a G note. Further down the fretboard we already memorised that D would be followed by a G and here it is again.

Thanks to memorising the top two bass strings we see those memorised collection of notes appearing as patterns elsewhere on the fretboard!

OK at this point we're now at a G, and we already know that on the low E string when we had a G we memorised that a C would be next to it. So coming back to the 5th fret of the 4th string, when we come across the G note we shouldn't be too surprised to find the adjacent string's 5th fret note (the 3rd treble string) will be a C note.

Let's continue on, the 5th fret of the 3rd string should then have an F on the adjacent B string right? As this is what we memorised from the top two bass strings (C is followed by F: "Cloud Formation" was the mnemonics I used). Well if that's what we were expecting we'd be wrong. It's actually an E note and not an F!

Crap! Has our pattern failed? No, it hasn't.

The reason the pattern didn't work for the B string is because the B string is the black sheep of the family.

Let me explain:

Each string is tuned a 4th higher from the preceding string. But the B string is the only string that isn't tuned to a 4th. It's actually a half step lower than expected (i.e. it is flattened) and is tuned to a 3rd degree.

So where I'd expect a F note on the string adjacent to the C. If we were to lower the F by a half-step we'd actually get an E note.

So in principle the pattern of the adjacent note following the memorised notes from the top two bass strings does kinda hold still, but it means for the B string you have to realise the adjacent note will be a half-step lower than the expectation.

Now what happens from here? Well the pattern continues on as it did before.

So if we now consider the next string along. We're at a E note currently on the 5th fret of the B string.

The adjacent string is the high E string, and at the fifth fret will be an A note. As per our pattern, we memorised "EA Sports". We know an E will be followed by an A.

The low E and the high E strings have the same notes

Finally, phew, if you're looking at a note on a string and you've already memorised the notes for the top two bass strings then you can also work backwards easily enough.

For example, if you're looking at the 8th fret of the high E string we'll already know this is a C note (as it matches what we've memorised on the low E string). So the note on the adjacent string preceding it (the B string), the note will be a G (as we've memorised already that G is followed by C).

This all can take some time to soak in. So what might be useful to you is to look again at the overlay of fretboard notes (see above) and just treat it like a word search puzzle. What patterns do you see that make sense to you? Find something that works and use it.

I personally found that memorising the notes of the top two bass strings, along with the string names, helped me identify a pattern that worked across the fretboard.

OK, so at this point we'll soon have an understanding of the notes on the fretboard and where they appear. But we'll now need to understand the relationship these notes have with a particular musical scale and the language used to define what makes up a musical scale.

The first step is to understand what an 'interval' is...

Intervals

An interval is the musical distance between two notes.

Intervals have two parts:

  1. Quantity
  2. Quality

Quantity

Quantity is the number of scale steps (degrees) in the major scale.

Note: we'll look at what the major scale is and the notes it consists of in the next section, but for now I want you to know that memorising the major scale is important. The biggest help is when you want to construct a chord (even if it's a minor or dominant sounding chord - both we'll discuss later - you'll still use the major scale to construct the chord)

The sequence of intervals between the notes of the major scale is:

W, W, H, W, W, W, H

The W represents a whole-step, which equates to 2 frets on the guitar fretboard.
The H represents a half-step, which equates to 1 fret on the guitar fretboard.

The following example demonstrates the A major scale, showing the quantity (steps/degrees) along with the intervals:

INTERVALS W W H W W W H
SCALE A B C♯ D E F♯ G♯ A
DEGREES 1 2 3 4 5 6 7 8

Notice the A has no interval. That is because it is the root note. It is what starts the scale. From there you move a set number of degrees (using the specified interval) to make up the rest of A's musical 'scale'.

Now don't worry about why there are specific notes being shown, we'll learn about this in the next section when we look at scales in more depth. But you might be wondering about the ♯ symbol? This is where the second part of an interval comes in, the symbol after the note will indicate the quality of the note being played...

Quality

The quality simply finalizes the actual note to be played by either adding/removing a sharp/flat.

In music, you can take a note such as A and either sharpen its tone so it becomes A♯; or you can flatten its tone so it becomes A♭. The act of sharpening or flattening a note is to move either up or down 1 fret from the note on the guitar's fretboard.

Later on you'll see that some notes can be named different things even though they have the same tone (or 'sound'). For example an A♯ can also be referred to as a B♭. We'll cover it later in more detail, but the only time it becomes relevant is when you're constructing music on sheet. This is because in some scenarios you could have a chord made up of multiple notes and need to construct a chord that has two A notes, which (on sheet music) isn't allowed. So for example, if you needed a chord constructed of both A and A♯ notes, then on sheet music that wouldn't make sense so you would have to write it as A and B♭ instead

To demonstrate this, look at the 5th fret down from the top of your guitar's fretboard. When pressing your finger down on the low E string at the 5th fret and strumming the string, you'll be playing an A note (assuming your guitar is in 'standard tuning').

If you now move your finger one fret 'up' (up in this case being towards to the top of your guitar's head), then you would have flattened the A note so it sounded lower than before. You'll be playing an 'A flat' A♭.

If (from the 5th fret again) you move your finger one fret 'down' (down in this case being away from the top of your guitar's head), then you would have sharpened the A note so it sounded higher in tone than before. You'll be playing an 'A sharp' A♯.

This is the fundamental principle behind the 'quality' of a note being played.

Which leads up onto the next point you should know, which is that there are two types of note qualities:

  1. Major
  2. Perfect

Note: the following information isn't immediately useful and so if it's a bit too much to memorise, feel free to come back to it at a later time

When we talk about a scale, we typically talk about a particular 'degree'.

For example, "play the 1st (root), 3rd and 5th degrees of the major scale".

The 2nd, 3rd, 6th, 7th steps/degrees of the major scale are called 'major':

  • Major Second
    • Equal to playing 1 whole-step from the root note
  • Major Third
    • Equal to playing 2 whole-steps from the root note
  • Major Sixth
    • Equal to playing 4 whole-steps and then 1 half-step from the root note
  • Major Seventh
    • Equal to playing 5 whole-steps and then 1 half-step from the root note

Look again at the table of intervals/scales/degrees earlier to see how the above information aligns with it.

But whether something is major can also depend on the scale being played (e.g. C harmonic minor has two flat notes and they're a Minor Third and a Minor Sixth).

The notes of the musical scale appear across all the strings. So for example, the 10th fret (low E string) is a D note. We could play the D note on the low A string (the 5th string) by pressing down on the A string at the 5th fret. We'll come back to the notes across the fretboard a later

The 1st, 4th, 5th, 8th scale steps/degrees are called perfect in quality:

  • Perfect Unison
    • Unison is the same note played twice (but basically, it's the root note)
  • Perfect Fourth
    • Every string is a 4th higher than the one below it
    • Except B string which is a Major 3rd higher
  • Perfect Fifth
    • Same note as found 5 frets on the adjacent (higher) string
    • Except B string whose same note is 4 frets on higher string
  • Perfect Octave
    • Octave is the name of the same note played at a higher frequency

The way I tend to remember this is:

Everything is "major" except the 1, 4, 5 progression

If you don't know what the 1, 4, 5 progression is don't worry as we'll cover that progression later. But for now all you need to know is that it is THE most well known progression in guitar music (so once you know the numbers you wont forget them).

You might say now, well what about the 8 (the Perfect Octave) how do you remember that is 'perfect' when it's not part of the 1, 4, 5 progression? Well it's just an octave higher than the 1 so it's generally easy to remember as you already know 1 is in the 1, 4, 5 progression so just think of the octave of 1 (again, don't worry too much about this as it's not really going to make a massive difference in learning how to play guitar at this stage).

Scales

It's important to note that scales don't describe any natural phenomenon but are just human invention - you can make up any scale that you want, and even simply ignore the concept of scales, and it won't make a difference.

Chromatic

The chromatic scale is a musical scale with twelve pitches, each a semi-tone above or below another:

A, A♯, B, C, C♯, D, D♯, E, F, F♯, G, G♯

Note: all the 'intervals' are half-steps

Diatonic

The diatonic scale is a musical scale with seven pitches (also known as 'heptatonic'), that are adjacent to one another on the circle of fifths.

A, B, C, D, E, F, G

The sharps and flats (which you saw as part of the chromatic scale) are not included as they are 'non-diatonic' notes.

Here are some examples...

The B diatonic scale:

B, C, D, E, F, G, A

The C diatonic scale:

C, D, E, F, G, A, B

Major

The major scale (or Ionian scale), like many musical scales, is made up of seven notes: the eighth duplicates the first at double its frequency, so it is referred to as a 'higher octave' of the same note.

The simplest major scale to write is C major, as it's the only major scale not to require sharps (♯) or flats (♭):

C, D, E, F, G, A, B

Here is another major scale, but in the key of B:

B, C♯, D♯, E, F♯, G♯, A♯, B (octave higher)

Here it is again, shown alongside the major scale intervals:

W W H W W W H
B C♯ D♯ E F♯ G♯ A♯ B

Here is one more example (in the key of F) that demonstrates the purpose of both ♯/♭ (see Accidentals below):

F, G, A, B♭, C, D, E, F (octave higher)

Here it is again, shown alongside the major scale intervals and degrees:

INTERVALS W W H W W W H
SCALE F G A B♭ C D E F
DEGREES 1 2 3 4 5 6 7 8

The important thing to note here is that the scale notes have to be in alphabetical order (meaning you can't have two notes from the same letter).

So you can see that the half-step from A doesn't make sense because that would result in an A♯.

So we need the tone to be a B, which means moving a half-step down from there gives us B♭ not A♯.

This becomes more important when you consider sheet music and how the key signature clef defines the sharps/flats for each note. You can't have a note be both sharp and flat and so flattening the B allows the clef to be clear on the tones (although their pitch sounds the same they are considered different tones/notes)

Minor

The minor scale (or Aeolian scale) is one of the diatonic scales.

It's also more commonly known as the "natural minor scale". This is because there are two other forms of minor scale that differ very slightly and so we need a way to identify them. There's also the "melodic minor scale" and the "harmonic minor scale".

Natural Minor Scale

The Am (A minor) scale:

A, B, C, D, E, F, G, A (octave higher)

Note: musical notes are typically written with an m to indicate a 'minor'

The sequence of intervals between the notes of a minor scale is:

W, H, W, W, H, W, W

Note: these intervals are the same as the major scale,
but notice the last two intervals are now shifted over to the start

Here is the same intervals represented in notes:

1 2 ♭3 4 5 ♭6 ♭7 8

Here it is again, shown alongside the minor scale intervals and degrees:

INTERVALS W H W W H W W
SCALE A B C D E F G A
DEGREES 1 2 3 4 5 6 7 8

Here is another minor scale, but in the key of B:

B, C♯, D, E, F♯, G, A, B (octave higher)

Here it is again, shown alongside the minor scale intervals and degrees:

INTERVALS W H W W H W W
SCALE B C♯ D E F♯ G A B
DEGREES 1 2 3 4 5 6 7 8

Melodic Minor Scale

W-H-W-W-W-W-H

Harmonic Minor Scale

W-H-W-W-H-WH-H

Pentatonic

A pentatonic scale is a musical scale or mode with five notes per octave in contrast to a heptatonic (seven-note) scale such as the major scale and minor scale.

Major

The major pentatonic scale is the major scale with the 4th and 7th degrees dropped.

Below is the Amaj pentatonic scale to demonstrate the dropped degrees:

W W H W W W H
A B C♯ D E F♯ G♯ A
1 2 3 4 (dropped) 5 6 7 (dropped)

This results in the Amaj pentatonic scale notes:

A, B, C♯, E, F♯

Minor

The minor pentatonic scale is the minor scale with the 2nd and 6th degrees dropped.

Below is the Amaj pentatonic scale to demonstrate the dropped degrees:

W H W W H W W
A B C D E F G A
1 2 (dropped) 3 4 5 6 (dropped) 7

This results in the Am pentatonic scale notes:

A, C, D, E, G

Circle of Fifths

The 'circle of fifths' is a visual representation of the relationships among the 12 tones of the chromatic scale.

Circle of Fifths

For example, if you want to play a I, IV, V chord progression in the key of C (find out about chord progressions below), then you can count the intervals (e.g. 1/C, 2/D, 3/E, 4/F, 5/G) or you can use the circle of fifths.

Notice in the circle of fifths, that a 5th forward is a V chord and a 5th backwards is a IV chord.

But how do you know if the chord is a sharp/flat? I'll demonstrate this below

Accidentals

Accidentals are made up of:

  • Naturals (♮)
  • Flats (♭)
  • Sharps (♯)

In musical notation, the sharp (♯), flat (♭), and natural (♮) symbols, among others, mark a note of a pitch that is not a member of the scale or mode indicated by the most recently applied key signature.

In practice, the following notes are naturals:

A, B, C, D, E, F, G

Note: in sheet music, the key signature will determine the sharp/flats and so you'll typically only see a natural (♮) used to denote that the note is neither sharp or flat

Where as the following notes are sharps/flats:

A♯/B♭, B♯/C B/C♭, C♯/D♭, D♯/E♭, E♯/F E/F♭,

Note: the above sharp/flat notes are actually the same note but are named differently depending on context these notes are known as being 'enharmonic'

Fret spacing for Intervals

To move a whole-step on the fretboard you would move up two frets on the same string OR three frets backwards on the higher string.

Note: two frets backwards for the B string

To move a half-step on the fretboard you would move up one fret on the same string OR four frets backwards on the higher string.

Note: three frets backwards for the B string

Modes

Modes are scales which have the same notes (but sound different because of the different relations to the tonic)

There are seven modes:

  1. Ionian (I)
  • Dorian (ii)
  • Phrygian (iii)
  • Lydian (IV)
  • Mixolydian (V)
  • Aeolian (vi)
  • Locrian (vii)

You'll notice below that each mode uses the same major scale, but each mode will shift the first interval to the end.

Ionian

W, W, H, W, W, W, H

Description: This scale is used as base scale from which other modes and scales come from
Quality: Happy or Upbeat quality
Musical Styles: Rock, Country, Jazz, Fusion
Chords: Major Chords

Dorian

W, H, W, W, W, H, W

Description: This is the major scale with a flat 3rd and 7th note
Quality: Jazzy, Sophisticated, Soulful
Musical Styles: Jazz, Fusion, Blues, and Rock
Chords: Minor, Minor 7th, Minor 9th

Phrygian

H, W, W, W, H, W, W

Description: This is the major scale with a flat 2nd, 3rd, 6th, and 7th note
Quality: Spanish Flavor
Musical Styles: Flamenco, Fusion, Speed Metal
Chords: Minor, Minor 7th

Lydian

W, W, W, H, W, W, H

Description: This is the major scale with a sharp 4th note
Quality: Airy
Musical Styles: Jazz, Fusion, Rock, Country
Chords: Major, Major 7th, Major 9th, Sharp 11th

Mixolydian

W, W, H, W, W, H, W

Description: This is the major scale with a flat 7th note
Quality: Bluesy
Musical Styles: Blues, Country, Rockabilly, and Rock
Chords: Dominant Chords

Aeolian

W, H, W, W, H, W, W

Description: This is the major scale with a flat 3rd, 6th, and 7th note
Quality: Sad, Sorrowful
Musical Styles: Pop, Blues, Rock, Heavy Metal, Country, Fusion
Chords: Minor Chords

Locrian

H, W, W, H, W, W, W

Description: This is the major scale with a flat 2nd, 3rd, 5th, 6th, and 7th note
Quality: Sinister
Musical Styles: Jazz, Fusion
Chords: Diminished, Minor 7th Flat Fives

Note: for complete breakdown of modes please refer to this wiki page.

Here is an example of the C major scale modes:

  • Ionian (I): C
  • Dorian (ii): Dm
  • Phrygian (iii): Em
  • Lydian (IV): F
  • Mixolydian (V): G
  • Aeolian (vi): Am
  • Locrian (vii): Bdim

Note: the notes match either major or minor depending on the mode so the Dorian mode is ii in Roman numerals
and that indicates minor, where as Lydian is uppercase roman numeral V which indicates a major Locrian is always diminished

Chords

Chords consist of notes from the major scale.

Progressions

Chord 'progressions' have functional names:

  • I: tonic
  • ii: supertonic
  • iii: mediant
  • IV: subdominant
  • V: dominant
  • vi: submediant
  • vii: leading note

Note: chords are typically written with an m to indicate a 'minor' or a maj to indicate a 'major' e.g. Am or Amaj7

You'll notice some of the roman numerals are lowercase and some are uppercase. This indicates whether the chord should be a minor or major (or in the case of the seventh, vii, it should be a diminished chord):

  • Minor: ii, iii, vi
  • Major: I, IV
  • Dominant: V
  • Diminished: vii

Example Progressions

Blues

A standard blues chord progression is:

I, IV, V

In the key of A this would be the chords:

  • A
  • D
  • E

As demonstrated below:

A B C D E F G
I ii iii IV V vi vii

Jazz

A standard jazz chord progression is:

ii, V, I

In the key of A this would be the chords:

  • Bm
  • E
  • A

As demonstrated below:

A B C D E F G
I ii iii IV V vi vii

Choose a progression

Imagine you want to play a I, IV, V progression in the key of B. Well, the simplest way to find the chords is to count the fourth and fifth numbers like so:

1 2 3 4 5 6 7 8
B C D E F G A B
√ √ √

But this isn't correct. The 2nd, 3rd and 5th chords are actually sharps! So how can you tell if that's the case?

Well, the solution is determined by the major scale intervals, like so:

1 2 3 4 5 6 7 8
B C♯ D♯ E F♯ G A B
√ √ √
W W H W W W H

Note: a whole-step from E is F#

Formulas

In order to determine the notes that make up a particular chord (and whether those notes should be a sharp or flat tone), we need to utilise intervals/degrees to find the notes and THEN flatten them.

Below are some examples. Try it. Count the intervals/degress in the major scale (e.g. W, W, H, W, W, W, H) and then write down the notes you find and THEN flatten them.

Note: you'll see further below that
Major == 1, 3, 5
Minor == 1, ♭3, 5
Diminished == 1, ♭3, ♭5

C (i.e. major)

1 2 3 4 5 6 7 8
C D E F G A B C
R W W H W W W H

Cm (i.e. minor)

1 2 ♭3 4 5 6 7 8
C D E♭ F G A B C
R W W H W W W H

Minors have a flattened 3rd
so although we say E♭,
it's also referred to as D♯

A (i.e. major)

1 2 3 4 5 6 7 8
A B C♯ D E F♯ G♯ A
R W W H W W W H

Am (i.e. minor)

1 2 ♭3 4 5 6 7 8
A B C D E F♯ G♯ A
R W W H W W W H

A whole step from B is 4 semi-tones C♯
We then flatten the note to C
As per the requirement for a minor chord (flat 3rd)

Adim (i.e. diminished)

1 2 ♭3 4 ♭5 6 7 8
A B C D E♭ F♯ G♯ A
R W W H W W W H

Diminished chords have a flattened 3rd and 5th
A whole step from B is 4 semi-tones C♯
We then flatten the note to C
And the 5th note from E to E♭
As per the requirement for a diminished chord

General pattern

When constructing the notes for a major chord we'll find the following pattern applies:

  • 4 semi-tones/half-tones between 1st and 3rd
  • 7 semi-tones/half-tones between 1st and 5th
  • 11 semi-tones/half-tones between 1st and 7th

Where as, if it's a minor chord, then we'll find a slightly modified pattern applies:

  • 3 semi-tones/half-tones between 1st and 3rd
  • 6 semi-tones/half-tones between 1st and 5th
  • 10 semi-tones/half-tones between 1st and 7th

Note: this is more 'for interest' than a recommendation to remember

Sevenths

Major 7 Dominant 7 Minor 7 Minor 7 ♭5
1, 3, 5, 7 1, 3, 5, ♭7 1, ♭3, 5, ♭7 1, ♭3, ♭5, ♭7

In music theory, the half-diminished seventh chord—also known as a half-diminished chord or a minor seventh flat five (m7♭5)—is formed by a root note, a minor third, a diminished fifth, and a minor seventh. Its consecutive intervals are minor 3rd, minor 3rd, major 3rd.

Note: any major 7th chord can be substituted for a minor 7th chord built on the 3rd of the original chord (this will provide a major 9th sound; e.g. musicians will often play an E minor 7th instead of a C major 7th in order to create a C major 9 harmony)

Triads

We saw these earlier in the section on Formulas, but just to recap them:

Major Minor
1, 3, 5 1, ♭3, 5

Augmented/Diminished

Here are the formulas for both an Augmented Triad and a Diminished Triad:

  • Augmented Triad: 1, 3, ♯5
  • Diminished Triad: 1, 3, ♭5

Augmented and Diminished seventh chords are the same as Augmented and Diminished triads but with a flat seventh note added:

  • Augmented Seventh: 1, 3, ♯5, ♭7
  • Diminished Seventh: 1, 3, ♭5, ♭♭7

Note: in the case of the diminished seventh, the 7th is lowered another half-tone

Other comments on this type of chord

To augment an interval you must increase its size (moving the notes farther apart).

To diminish an interval you must decrease its size (moving the notes closer together).

With augmented chords you should:

  • Raise the note by ½ when ascending
  • Drop the note by ½ when descending

With diminished chords you should:

  • Drop the note by ½ when ascending
  • Raise the note by ½ when descending

A major 2nd, 3rd, 6th, 7th become augmented in quality when they're increased by a half-step in size (or minor when decreased, and then diminished if decreased again).

A perfect 1st (unison), 4th, 5th, 8th (Octave) become 'either' augmented or diminished in quality when they're increased or decreased by a half-step.

When changing the quality of an interval/degree that already has an accidental, you might end up seeing double accidentals, like ♭♭ and ♯♯. This is rare, but theorectically correct.

Names and Symbols

When you see chords written down, you'll see a variety of different names and symbols used.

A great resource for this particular topic is Wikipedia's page on the topic of names/symbols

The following examples are some common ones (I'm using a C that includes a seventh note for my examples):

  • Major (1, 3, 5, 7): Cmaj7, CM7, CΔ7
  • Minor (1, ♭3, 5, ♭7): Cmin7, Cm7, C−7
  • Dominant (1, 3, 5, ♭7): CDom7, C7
  • Augmented (1, 3, ♯5 ♯7): Caug7, C+7
  • Diminished (1, ♭3, ♭5, ♭♭7): Cdim7, C♭7, C°7, Co7
  • Half Diminished/Minor Seventh Flat 5 (1, ♭3, ♭5, ♭7): Cø7, CØ7
  • Minor-Major Seventh (1, ♭3, 5, 7): Cm(M7), Cm(maj7), Cmin(maj7), Cmin(M7) †

† see minor-major seventh Wikipedia page for lots of extra names/symbols

Learning Order

The following order is thought to be a sensible approach to learning each chord type:

  1. Major 7 / Minor 7
  • Major / Minor
  • Dominant 7
  • Minor 7 ♭5
  • Augmented / Diminished

Families

There are three tonal families:

  1. Tonic: 1, 3, 6
  2. Sub-Dominant: 2, 4
  3. Dominant: 5, 7

Any of these family chords can be substituted with another chord from their family (inc. different voicings & inversions).

Note: Sub-Dominant is considered a 'passing' family that tries to bridge the gap between the other two

This means, for example, you could decide to swap a 1 chord for a 3rd or 6th chord.

So if we look back at an earlier section called 'progressions', there we described how a 1 chord of a progression (the root) is typically major in quality, a 3rd within the progression is minor in quality and a 6th is also minor/diminished in quality.

Consider again our wish to swap a 1 for a 3rd or 6th. If our chord progression was a standard 1, 4, 5 progression in the key of C, then this would be the chords Cmaj7, Fmaj7, G7. So based on our new knowledge of chord 'families', we now know that we can swap the Cmaj7 for either a Em7 (3rd) or a Am7 (6th).

Relative Chords

Relative chords (and scales) are those that have (almost †) the same notes but differ in tone by their major and minor qualities.

With relative chords you can substitute a major for its relative minor (and vice versa) without too drastically changing the tone of the song or its progression.

This is really useful theory to know about, because in some songs (especially Jazz) you'll at some point hit a confusing set of chords that don't appear to match up to the progression the music sheet is telling you the song is using. It's likely in these situations that the questionable chord has been swapped for its relative chord (e.g. you're expecting to see a Cmaj7 but the music sheet says to play an Amin7)

One way to identify a chord's relative minor (or major) equivalent is to use the Circle of Fifths.

Here follows is an explanation of the how and why of relative chords...

If you're playing a major scale and you want to identify its relative minor scale, you look at the 6th interval of the major scale (Root (1), W (2), W (3), H (4), W (5), W (6), W (7), H (8/Octave)) and that will give you the relative minor scale (e.g. C major's scale 6th interval is an A, so A minor scale is the relative minor scale).

Similarly, if you're playing a minor scale and you want to identify its relative major scale, you look at the 3rd interval of the minor scale (Root (1), W (2), H (3), W (4), W (5), H (6), W (7), W (8/Octave)) and that will give you the relative major scale (e.g. A minor's scale 3rd interval is a C, so C major scale is the relative major scale).

On the fretboard you can figure this out very quickly by using the low E string (the 6th string). So for finding the relative minor you can simply move 3 notes down from the major note (these are half steps and don't include the major note itself). For finding the relative major you can simply move 3 notes up from the minor note (these are half steps and don't include the minor note itself).

To understand why specifically the 3rd and 6th intervals, then look back at the previous section on 'Families' which shows the 'tonic' family consists of 1, 3 and 6.

Here also is a useful video that demonstrates this concept: https://www.youtube.com/watch?v=FJQ3aux1v5Q

† here's an example of how the notes aren't quite the same, but almost:
Cmaj7 vs Am7 (the only difference is that the C's 7th note - B - becomes the root A note in Am7)
Directly below is a comparison of the notes of each of these chords...

Cmaj7

1, 3, 5, 7
C, E, G, B

Am7

1, ♭3, 5, ♭7
A, C, E, G

Timings

  • 4 beats per bar/measure:
    1, 2, 3, 4
  • 8 beats per bar/measure:
    1 &, 2 &, 3 &, 4 &
  • 12 beats per bar/measure:
    1 trip let, 2 trip let, 3 trip let, 4 trip let
  • 16 beats per bar/measure:
    1 e & ah, 2 e & ah, 3 e & ah, 4 e & ah

Example Chords

Remember that the notes in the tables are flattened as per the minor/dominant requirements, but after we've gone through and calculated all the notes as per the major scale.

So for example Am7. We calculate the notes as per the major scale (A B C♯ D E F♯ G♯ A), then we flatten the 3rd and 7th notes (A B [C] D E F♯ [G] A).

Amaj7

1, 3, 5, 7
A, C♯, E, G♯

1 2 3 4 5 6 7 8
A B C♯ D E F♯ G♯ A
R W W H W W W H

Am7

1, ♭3, 5, ♭7
A, C, E, G

1 2 ♭3 4 5 6 ♭7 8
A B C D E F♯ G A
R W W H W W W H

A7 (dominant)

1, 3, 5, ♭7
A, C♯, E, G

1 2 3 4 5 6 ♭7 8
A B C♯ D E F♯ G A
R W W H W W W H

Bmaj7

1, 3, 5, 7
B, D♯, F♯, A♯

1 2 3 4 5 6 7 8
B C♯ D♯ E F♯ G♯ A♯ B
R W W H W W W H

Bm7

1, ♭3, 5, ♭7
B, D, F♯, A

1 2 ♭3 4 5 6 ♭7 8
B C♯ D E F♯ G♯ A B
R W W H W W W H

B7 (dominant)

1, 3, 5, ♭7
B, D♯, F♯, A

1 2 3 4 5 6 ♭7 8
B C♯ D♯ E F♯ G♯ A B
R W W H W W W H

Cmaj7

1, 3, 5, 7
C, E, G, B

1 2 3 4 5 6 7 8
C D E F G A B C
R W W H W W W H

Cm7

1, ♭3, 5, ♭7
C, E♭, G, B♭

1 2 ♭3 4 5 6 ♭7 8
C D E♭ F G A B♭ C
R W W H W W W H

C7 (dominant)

1, 3, 5, ♭7
C, E, G, B♭

1 2 3 4 5 6 ♭7 8
C D E F G A B♭ C
R W W H W W W H

Dmaj7

1, 3, 5, 7
D, F♯, A, C♯

1 2 3 4 5 6 7 8
D E F♯ G A B C♯ D
R W W H W W W H

Dm7

1, ♭3, 5, ♭7
D, F, A, C

1 2 ♭3 4 5 6 ♭7 8
D E F G A B C D
R W W H W W W H

D7 (dominant)

1, 3, 5, ♭7
D, F♯, A, C

1 2 3 4 5 6 ♭7 8
D E F♯ G A B C D
R W W H W W W H

Emaj7

1, 3, 5, 7
E, G♯, B, D♯

1 2 3 4 5 6 7 8
E F♯ G♯ A B C♯ D♯ E
R W W H W W W H

Em7

1, ♭3, 5, ♭7
E, G, B, D

1 2 ♭3 4 5 6 ♭7 8
E F♯ G A B C♯ D E
R W W H W W W H

E7 (dominant)

1, 3, 5, ♭7
E, G♯, B, D

1 2 3 4 5 6 ♭7 8
E F♯ G♯ A B C♯ D E
R W W H W W W H

Fmaj7

1, 3, 5, 7
F, A, C, E

1 2 3 4 5 6 7 8
F G A B♭ C D E F
R W W H W W W H

Fm7

1, ♭3, 5, ♭7
F A♭ C E♭

1 2 ♭3 4 5 6 ♭7 8
F G A♭ B♭ C D E♭ F
R W W H W W W H

F7 (dominant)

1, 3, 5, ♭7
F A C E♭

1 2 3 4 5 6 ♭7 8
F G A B♭ C D E♭ F
R W W H W W W H

Gmaj7

1, 3, 5, 7
G B D F♯

1 2 3 4 5 6 7 8
G A B C D E F♯ G
R W W H W W W H

Gm7

1, ♭3, 5, ♭7
G B♭ D F

1 2 ♭3 4 5 6 ♭7 8
G A B♭ C D E F G
R W W H W W W H

G7 (dominant)

1, 3, 5, ♭7
G B D F

1 2 3 4 5 6 ♭7 8
G A B C D E F G
R W W H W W W H

Patterns?

A C E G
        B D F A
  C E G B
          D F A C
    E G B D
            F A C E
      G B D F

Other Chords

Power Chords

A 'power chord' is really just a 'fifth chord'.

So, for example, if you wanted a C power chord you would say C5.

They are made up of the root of the key and its fifth.

But you can also make the sound a little 'fuller' by repeating the root.

Suspended Chords

A 'suspended chord' is typically one where the 3rd degree is omitted and replaced with either a perfect fourth or a major second. So you might see it defined as a 'suspended 4th' or 'suspended 2nd'.

Suspended chords are neither major nor minor in tone (as that is typically determined by the 3rd degree).

The purpose of these types of chords is to allow a smoother transition between major and minor scales.

If you see a chord defined as (for example) G7sus then it likely suggests including both the 2nd and 4th degrees. Otherwise you'll typically see an explicit G7sus4 or G7sus2. In the case of G7sus, the way to play that on the guitar would require dropping not only the 3rd but also the 5th (which is a fairly neutral tone so is fairly safe to substitute).

6th

A sixth chord has the following intervals:

1, 3, 5, 6

It's like a major 7th but just swap the 7th for a 6th.

Note: although the 6th and 13th notes sit at equivalent intervals (i.e. an octave apart), the term 13th (1, 3, 5, ♭7, 9, 11, 13) is used for dominant chords, and 6 is used for major family chords to help differentiate them on a leadsheet

The 6th's Chord Name/Symbol

A Cmaj6 (1, 3, 5, 6) can be written as C6. But don't confuse this for a dominant chord.

Although a major triad with a flattened 7th note is considered 'dominant' in tone and is written (for example) as C7; there is no such 'dominant' for a 6th note chord.

By this we mean, typically you don't see a major chord with a flat 6th. Although, really, there are no boundaries in music that can't/shouldn't be crossed. It's obviously a decision that is completely up to the guitarist/musician to play that collection of notes if they so choose to.

Slash Chords (e.g. C6/9)

Typically when you see a slash chord you think of inversions (see later in this doc), but in some instances it is used as a shorter syntax for an 'add' style chord. So with C6/9 this indicates a Cmaj6 with an added 9th note.

Diminished 7th

Note: we saw this earlier; what follows is just a recap

The diminished seventh is made up of a diminished triad (i.e. a minor triad with a lowered fifth: 1, ♭3, ♭5) and a diminished seventh interval.

The diminished seventh interval is a minor seventh that has been lowered a half note (identical to a straightforward sixth).

So in practice it's 1, ♭3, ♭5, 6 (or possibly more correctly would be to say: 1, ♭3, ♭5, ♭♭7).

This chords have a dissonant sound. They have lots of tension and so are primarily used in Jazz.

9th

The easiest way to make a ninth is to raise the root by a single tone so it becomes the 2nd interval. So although a 9th is actually the 2nd degree one octave higher, by playing the 2nd you're at least getting the 9th quality into the chord sound.

This is also ok if the root note is handled by the bass player.

Otherwise if you still need the root sound, then you'll need to add the ninth to your 7th chord (1, 3, 5, 7, 9). Just remember the 5th is a neutral note and can be safely dropped to make adding a 9th a little easier.

Don't also forget relative chords. If you have a minor or major 7th chord that you want to make into a 9th, then you can consider swapping the chord for its relative minor or major as the relative chord might be easier to play with a 9th.

11th

To make an eleventh chord you can substitute the 5th (as it's a fairly neutral tone) by lowering it a whole tone to a 4th.

Remember the 5th, when played an octave higher, is really a 12th degree.

Similarly by lowering to a 4th you get a 11th at an octave higher.

13th

To make an thirteenth chord you can substitute the 5th (as it's a fairly neutral tone) by raising it a whole tone to a 6th.

Remember the 5th, when played an octave higher, is really a 12th degree.

Similarly by raising to a 6th you get a 13th at an octave higher.

Voicings, Inversions and Drop Voicings

In simple terms, a 'voicing' is a guitar chord that is played in a different position.

Inversions are where you play the notes of a chord, but change the 'bass' note to no longer be the root note.

Drop Voicings are a further extension of this idea, where you move the nth highest note to be the bass note.

The fundamental difference between inversions and drop voicings are described in more detail below, but it's important to realise that the order of notes (beyond the bass note) can be played in any order so you will find a dizzying array of voicing options.

One last thing to comment on is that on the guitar most of these voicings are (close to) unplayable because they would require very wide stretches. This is where 'drop' voicings come into play as they are easier to play on a guitar.

In practice this is what is meant by 'closed voicings' and 'open voicings'. The former is where the notes are within the same octave; where as the latter means the notes after the bass are spread out over a large octave range.

Inversions

There are n number of inversions for a chord.

So a triad has 3 inversions (as there are 3 notes that make up a triad chord).

So that's 3 different voicings for a triad chord you can play.

Where as a Seventh chord has 4 inversions (as there are typically 4 notes that make up a seventh chord).

So that's 4 different voicings for a seventh chord you can play.

With inversions we always have a 'root' inversion, followed by a numbered inversion for the remaining number of notes.

So a triad (3 notes) will have:

  1. Root inversion
  2. 1st inversion
  3. 2nd inversion

Where as a seventh (4 notes) will have:

  1. Root inversion
  2. 1st inversion
  3. 2nd inversion
  4. 3rd inversion

If our chord is Cmaj7 then its intervals looks like 1, 3, 5, 7. Meaning, our numbered inversions - remember an inversion is just changing the bass note - will no longer have C as the bass note but whichever note we've moved into the bass note position.

BUT (and importantly), when moving the selected note into the bass position, we must re-order the remaining notes.

Note: don't worry, we demonstrate a real example of this below

Drop Voicings

A drop voicing changes the bass note - much like an inversion does - but it has a different process for deciding which note to move into the bass position. Where with inversions we move up the intervals one by one from the low end, the drop voicings are determined by their name and start from the high end of the notes rather than the low end.

So if you had a 'Drop 2' voicing then you'd pick the second highest note from the chord and move that into the bass position. Effectively we 'drop' the note down an octave.

Now the additional difference is that we don't re-order the remaining notes

Note: again, don't worry, we demonstrate a real example of this below

Table Example

The following table will hopefully demonstrate the above concepts better.

We'll be using a Drop 2 Voicing on the Cmaj7 chord.

The table will show what the standard 'inversions' for a Cmaj7 look like, and then the Drop 2 Voicings that you can get out of it as well.

Effectively the thing I would like you to come away with after reading this is:
"wow, I have many different variations and tones I can achieve with just one chord"

Voicing Intervals Drop 2 Intervals Notes for Cmaj7 Drop 2 Degrees
Root inversion 1, 3, 5, 7 5, 1, 3, 7 C, E, G, B G, C, E, B
1st inversion 3, 5, 7, 1 7, 3, 5, 1 E, G, B, C B, E, G, C
2nd inversion 5, 7, 1, 3 1, 5, 7, 3 G, B, C, E C, G, B, E
3rd inversion 7, 1, 3, 5 3, 7, 1, 5 B, C, E, G E, B, C, G

Improvisation

There are three levels of tension:

  1. Chord notes
  2. Scale notes
  3. Remaining notes

When playing over a C chord you want to play notes that are found in the C chord (C 1st, E 3rd, G 5th), and you can resolve to any of those notes and things will sound fine. But that alone doesn't sound very advanced so you need to introduce some tension.

The next level of tension to add are the C scale notes that aren't part of the C chord (D 2nd, F 4th, A 6th, B 7th), and you add these as 'passing notes': so notes that you hit before resolving to a chord note. This helps your improvisation sound better but there's still more tension you can add.

Finally the last level of tension is to add are any notes that remain from the 12 notes available in the scale that aren't either a chord note, nor a scale note (A♯, C♯, D♯, F♯, G♯).

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