In response to @celeenr's (https://twitter.com/celeenr) RubyConf 2016 talk "Rhythmic Recursion"

💩 🚌👏 .rb

class Voice
  BASELINE = %w( there is no - poop ing - on - the  bus - )
  VOICES   = `say -v '?'`.lines.map { |line| line.split.first }

  def initialize &voice
    @voice, @i = voice, -1
  end

  def perform
    advance
    Thread.new do
      @voice.(BASELINE[@i], @i) unless BASELINE[@i] == "-"
    end
  end

  def advance
    @i = (@i + 1) % BASELINE.length
  end
end

a = Voice.new do |word,_|
  system "say -r 250 -v Alice #{word}"
end
b = Voice.new do |word,_|
  vol = word == "there" ? 1 : 0.5
  system "afplay -v #{vol} /System/Library/Sounds/Tink.aiff"
end

13.times do
  (Voice::BASELINE.length * 4).times do
    a.perform
    b.perform
    sleep 0.15
  end
  a.advance
end