guitar rainbows

rainbow.py

import mido
from pippi import dsp, tune

out = mido.open_output('UltraLite AVB MIDI 1')
channel = 0

def play(freqs, length=44100):
    if dsp.rand() > 0.5:
        freqs.reverse()

    for freq in freqs:
        amp = dsp.rand(0.01, 1)
        velocity = int(round(amp * 127.0))
        freq *= 2**dsp.randint(0,3)

        note = int(round(tune.ftom(freq)))
        bit = dsp.mstf(10, 160)
        length -= bit
        out.send(mido.Message('note_on', note=note, velocity=velocity))
        dsp.delay(bit)

    dsp.delay(length)

    for freq in freqs:
        if dsp.rand() > 0.25:
            note = int(round(tune.ftom(freq)))
            out.send(mido.Message('note_off', note=note, velocity=0))

chords = ['IV', 'IV6', 'IV6', 'iii', 'III', 'vii*'] * 4
for chord in chords:
    freqs = tune.chord(chord, octave=2, key='e')
    print chord, freqs
    play(freqs * dsp.randint(1, 4), dsp.stf(0.75, 1.5))