[groovy]play midi

sakura.groovy

// groovy sakura.groovy
import javax.sound.midi.*

// compose sequence

ticks = 16
// compose utils
def addNote(track, pitch, start, duration=ticks, velocity=64) {
  // pitch: C=60, D=62, E=64, F=65, G=67, A=69, B=71, ...
  // start: absolute time
  // duration: 1/4 = ticks
  // velocity: 0 <= soft < 64 < hard <= 127
  // returns: end time
  message = new ShortMessage()
  message.setMessage(ShortMessage.NOTE_ON, pitch, velocity)
  track.add(new MidiEvent(message, start))
  message = new ShortMessage()
  message.setMessage(ShortMessage.NOTE_OFF, pitch, velocity)
  track.add(new MidiEvent(message, start + duration))
  return start + duration
}
def instChange(track, instNo=0) {
  // instNo: 0-127, default 0
  message = new ShortMessage()
  message.setMessage(ShortMessage.PROGRAM_CHANGE, 0, instNo, 0)
  track.add(new MidiEvent(message, 0))
}

A1=57; B1=59; C1=60; D1=62; E1=64; F1=65; G1=67; A2=69; B2=71; C2=72
d1=ticks*4; d15=ticks*3; d2=ticks*2; d4=ticks; d8=ticks/2 as int

// from http://en.wikipedia.org/wiki/Sakura_Sakura
score = [
  [A2, d4], [A2, d4], [B2, d2],
  [A2, d4], [A2, d4], [B2, d2],
  [A2, d4], [B2, d4], [C2, d4], [B2, d4],
  [A2, d4], [B2, d8], [A2, d8], [F1, d2],
  
  [E1, d4], [C1, d4], [E1, d4], [F1, d4],
  [E1, d4], [E1, d8], [C1, d8], [B1, d2],
  [A2, d4], [B2, d4], [C2, d4], [B2, d4],
  [A2, d4], [B2, d8], [A2, d8], [F1, d2],
  [E1, d4], [C1, d4], [E1, d4], [F1, d4],
  [E1, d4], [E1, d8], [C1, d8], [B1, d2],
  
  [A2, d4], [A2, d4], [B2, d2],
  [A2, d4], [A2, d4], [B2, d2],
  [E1, d4], [F1, d4], [B2, d8], [A2, d8], [F1, d4],
  [E1, d2], [null, d2],
]

// edit track
seq = new Sequence(Sequence.PPQ, ticks)
track = seq.createTrack()
instChange(track, 107)
t = 0
score.each { pitch, duration ->
  t = pitch ? addNote(track, pitch, t, duration) : t + duration
}


// play 
seqr = MidiSystem.sequencer
seqr.tempoInBPM = 72.0
seqr.sequence = seq
seqr.open()

seqr.start()
while (seqr.isRunning()) Thread.sleep(1000)
seqr.close()