Permuto for Sonic Pi

20210523b-permuto.rb

bpm = 400
palette = 28
dilution = 14
length = 16
noteLength = 1
chance = 0.5
velocityMax = 0.3
velocityMin = 0.2

seed = Time.new.to_i
seed = 1621788316
sequence = Array.new(length, { morpheme: nil })

domain = scale(0, :aeolian, num_octaves: 10)

use_bpm(bpm)
use_random_seed(seed)
use_synth(:saw)
use_midi_defaults(port: "port_2")

use_midi_logging(false)

puts(seed)

midi_all_notes_off()

define :randUnit do
  morpheme = rand_i(palette + dilution)
  
  return (morpheme >= palette) ? { morpheme: nil } : { morpheme: morpheme, velocity: (velocityMin + (rand * (velocityMax - velocityMin))) }
end

live_loop :perform do
  for unit in sequence
    morpheme = unit[:morpheme]
    velocity = unit[:velocity]
    midi(domain[morpheme + 21], channel: 1, sustain: (noteLength - 0.05), vel_f: velocity) if !morpheme.nil?
    wait(noteLength)
  end
  (0...sequence.length).each do |i|
    sequence[i] = randUnit() if (rand < chance)
  end
end