Sonic Pi: Basic Quantized Drum Beat

basic-quantized-drum-beat.rb

# Sonic Pi (http://sonic-pi.net/)
# Basic Quantized Drum Beat

# Globals
$bpm = 128
$bps = $bpm / 60
$qunatize = 1.0 / 32.0

# Helper step sequencing method
def sync_steps(steps, quantize = 1.0 / 4.0)
  step_count = 0
  loop do
    sync :tick
    step_count += ($qunatize / quantize)
    if step_count >= steps
      break
    end
  end
end

# Definitions for basic drum beats
def hat_pedal
  sample :drum_cymbal_pedal
end

def hat_closed
  sample :drum_cymbal_closed
end

def kick
  sample :drum_heavy_kick
end

# Simple Four-on-the-floor beat
def song
  in_thread do
    loop do
      kick
      sync_steps(4)
    end
  end

  in_thread do
    loop do
      3.times do
        sync_steps(2)
        hat_closed
        sync_steps(2)
      end
      sync_steps(2)
      hat_pedal
      sync_steps(1)
      hat_pedal
      sync_steps(1)
    end
  end
end

# Queue the song
in_thread do
  sync :tick
  song
end

# Start up the sync thread using global quantization
in_thread do
  loop do
    cue :tick
    sleep $qunatize / $bps
  end
end