Javaで作曲した (題名："837799")

初期値837799のコラッツ数列をmod 127を演算してMIDIの音階にしてみました。
こちらで聴けます。
https://soundcloud.com/user783056320/837799a

package collatz;

import java.math.BigInteger;

import javax.sound.midi.Instrument;
import javax.sound.midi.MidiChannel;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Synthesizer;

public class Collatz {
	  public static void main(String[] args){
		    MidiChannel channel = null;
		    try {
		      Synthesizer synthesizer = MidiSystem.getSynthesizer();
		      synthesizer.open();
		      Instrument[] instruments = synthesizer.getDefaultSoundbank().getInstruments();
		      synthesizer.loadInstrument(instruments[0]);
		      channel = synthesizer.getChannels()[0];
              soundCollatz(channel, new BigInteger("837799"));
		      synthesizer.close();
		    } catch(Exception e){
		      if(channel != null)  channel.allNotesOff();
		    }
		    System.exit(0);
		  }
	  
	  public static BigInteger collatz(BigInteger n){
		  if(n.mod(new BigInteger("2")).compareTo(new BigInteger("0")) == 0){
			  return n.divide(new BigInteger("2"));
		  }else{
			  return n.multiply(new BigInteger("3")).add(new BigInteger("1"));
		  }
	  }
	  
	  public static void soundCollatz(MidiChannel channel, BigInteger n) throws InterruptedException{
		  BigInteger a = n;
		  while(a.compareTo(new BigInteger("1")) != 0){
			  System.out.println(a);
			  sound(channel, a.mod(new BigInteger("127")).intValue());
			  a = collatz(a);
		  }
	  }
	  
	  public static void sound(MidiChannel channel, int n) throws InterruptedException{
	      channel.noteOn(n , 127);
	      Thread.currentThread();
		  Thread.sleep(256);
	      channel.noteOff(128);
	  }
}