Randomised drum groove

README.md

Randomised drum groove

More Sonic Pi experiments with randomisation of grooves.

By choosing the likelihood of certain sounds landing on certain beats we can create grooves that are unique and non-repeating yet not totally random - they maintain some feeling of a style or genre.

I'm looking to develop this idea to express these kinds of patterns in a declarative way. Any feedback to @xavriley on twitter please.

You can download Sonic Pi here: http://sonic-pi.net/get-v2.0

randobeat.rb

define :randobeat do

  # by playing with the "length" of onbeats vs offbeats
  # we get different groove feelings
  sleep_times = [0.25, 0.25]
  sleep_times = [0.23, 0.27] if one_in(4)
  sleep_times = [0.27, 0.23] if one_in(8)

  (1..16).to_a.each do |i|
    sample :drum_bass_hard if i == 1
    with_fx :reverb, mix: 0.01 do
      synth :cnoise, attack: 0.0, sustain: 0, decay: 0.1, release: 0.05 if i == 9
      #synth :cnoise, attack: 0.0, sustain: 0, decay: 0.05, release: 0.12 if (i == 1 and one_in(8))
      #synth :cnoise, attack: 0.0, sustain: 0, decay: 0.05, release: 0.12 if (i == 15 and one_in(8))
    end

    if [1,5,9,13].include? i
      # strong beats
      sample :drum_cymbal_closed
    elsif one_in(3) and [3,7,11,15].include? i
      # offbeat 8ths
      sample :drum_cymbal_closed
      sample :drum_bass_hard if one_in(6)
    elsif one_in(5)
      # offbeat 16ths
      sample :drum_cymbal_closed
      sample :drum_bass_hard if one_in(6)
    end

    sleep sleep_times.first if i.odd?
    sleep sleep_times.last if i.even?
  end
end

in_thread(name: :beat) do
  loop { randobeat }
end