4_ways_for_doing_12-TET.csd

Four ways for doing Twelve-tone Equal Temperament
Jacob Joaquin
September 22, 2010
[email protected]
csoundblog.com

<CsoundSynthesizer>
<CsInstruments>
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1
0dbfs = 1

gisine ftgen 1, 0, 8192, 10, 1

; Hertz
instr 1
    ifreq = p4

    a1 foscil 0.707, ifreq, 1, 1, 1, gisine
    out a1
endin

; cpspch
instr 2
    ipch = cpspch(p4)

    a1 foscil 0.707, ipch, 1, 1, 1, 1
    out a1
endin

; Half step (relative to A440)
instr 3
    ihalf_step = 440 * 2 ^ (p4 / 12)

    a1 foscil 0.707, ihalf_step, 1, 1, 1, 1
    out a1
endin

; MIDI note
instr 4
    imidi_note = 440 * 2 ^ ((p4 - 69) / 12)

    a1 foscil 0.707, imidi_note, 1, 1, 1, 1
    out a1
endin

</CsInstruments>
<CsScore>

t 0 120

; Hertz
i 1 0 0.5 440
i 1 + .   880
i 1 + .   783.946655
i 1 + .   698.436707
i 1 + .   659.217957
i 1 + .   587.312988
i 1 + .   554.333984
i 1 + .   466.137451

; cpspch
i 2 4 0.5 8.09
i 2 + .   9.09
i 2 + .   9.07
i 2 + .   9.05
i 2 + .   9.04
i 2 + .   9.02
i 2 + .   9.01
i 2 + .   8.10

; Half step (relative to A440)
i 3 8 0.5 0
i 3 + .   12
i 3 + .   10
i 3 + .   8
i 3 + .   7
i 3 + .   5
i 3 + .   4
i 3 + .   1

; MIDI note
i 4 12 0.5 69
i 4 +  .   81
i 4 +  .   79
i 4 +  .   77
i 4 +  .   76
i 4 +  .   74
i 4 +  .   73
i 4 +  .   70

</CsScore>
</CsoundSynthesizer>