ex-generative.rb

#
# ex-generative.rb
#  ported from https://github.com/naokinomoto/ex_music_sandbox/blob/master/lib/piece/generative_sup.ex
#
use_bpm 55

c_major_scale = scale(:C4, :major, num_octaves: 2) # :C4 = 60
puts c_major_scale

r = 3.8
x = 0.1
live_loop :Logistics do
  idx = (c_major_scale.length * x).ceil
  #  puts "idx: #{idx}"
  m = c_major_scale[idx]

  use_synth :fm
  if rand_i(3) > 0
    play m, sustain: 1.0 * 1 / 16, amp: 1
  end
  sleep 1.0 * 2 / 16

  x = r * x * (1 - x)
  # puts "x: #{x}"
end

chord_chain_dict = {
  I:   [:ii, :iii, :IV, :V, :vi, :vii],
  ii:  [:V, :vii],
  iii: [:IV, :vi],
  IV:  [:ii, :V, :vii],
  V:   [:vi, :I],
  vi:  [:ii, :IV, :V],
  vii: [:I]
}
puts chord_chain_dict
deg = :I
live_loop :Markov do
  d = deg.downcase
  sc = d == deg ? :minor : :major
  use_synth :fm
  play chord_degree(d, :C4, sc),
    sustain: 1.0 * 6 / 16, amp: 1
  sleep 1.0 * 12 / 16

  next_chords = chord_chain_dict[deg]
  idx = rand_i(next_chords.length)
  deg = next_chords[idx]
end

live_loop :Prob do
  bd = ring(10, 0, 2, 0,  6, 0, 2, 0,  3, 0, 6, 0,  1, 0, 2, 4).tick(:bd)
  if rand_i(10) < bd
    sample :bd_haus, amp: 5
  end

  sd = ring(0,  0, 1, 0,  1, 0, 6, 0,  6, 0, 1, 0,  1, 0, 6, 0).tick(:sd)
  if rand_i(10) < sd
    sample :sn_dolf
  end

  ch = ring(10, 2, 8, 2,  1, 2).tick(:ch)
  if rand_i(10) < ch
    sample :drum_cymbal_closed
  end

  oh = ring(0,  0, 0, 0,  9, 0, 0, 0,  0, 0, 0, 0,  0, 0, 9, 0).tick(:oh)
  if rand_i(10) < oh
    sample :elec_cymbal, amp: 0.5
  end

  sleep 1.0 * 1 / 16
end

https://soundcloud.com/kn1kn1/ex-generative