B13 GuitMuso

InYourFaces.php

<?php

// Frequency hertz()
// PitchClass::A::B::C::D::E::F::G
// Accidental::NATURAL::SHARP::FLAT
// Octave number()
// Note pitchClass() accidental() octave()
# note is defined by frequency(Hz) but can translate into pitchClass/accidental/octave
# mode is made up of intervals
# scale is a mode starting from a tonic, or set of notes with key
# chord is a key with a set of notes, pitch classes, or intervals

interface Frequency
{
    public function hertz():float;
    public static function createNote(Note $note):Frequency;
    public static function create(float $frequency = 440.0):Frequency;
    public static function createComponents(string $pitchClass, string $accidental, int $octave):Frequency;
}

interface PitchClass
{
    const A = 'A';
    const B = 'B';
    const C = 'C';
    const D = 'D';
    const E = 'E';
    const F = 'F';
    const G = 'G';
}

interface Accidental
{
    const NATURAL = '';
    const SHARP = '#';
    const FLAT = 'b';
}

interface Octave
{
    public function number():int;
}

interface Beat {
    public function duration():int;
}

interface Note
{
    public function pitchClass():PitchClass;
    public function accidental():?Accidental;
    public function octave():?Octave;
}

interface Interval {}
interface IntervalSet {}
interface NoteSet {}
interface Tonic extends Note {}
interface Chord {}
interface Scale {} // tonic, pitchClassSet
interface Mode {} // intervalSet
// --->>> Instrument Definition <<<--- //
interface String {}
interface Medium {}
interface Guitar extends Medium {}