<SCRIPT SRC='midi.js'></SCRIPT>
This is a very simple example to play music from your keyboard.
<br>
Press Q to play C, W for D, E for E, etc.
<SCRIPT>
function play_note(note_name) {
  var noteEvents = [];
  [note_name].forEach(function(note) {
      Array.prototype.push.apply(noteEvents, MidiEvent.createNote(note));
  });
  var track = new MidiTrack({ events: noteEvents });
  var song  = MidiWriter({ tracks: [track] });
  //alert(song.b64);
  song.play();
}

function manejador(elEvento) {
  var evento = elEvento || window.event;
  if (evento.keyCode==81)
  {
  //Q
  play_note("C5");
  }
  if (evento.keyCode==87)
  {
  //W
  play_note("D5");
  }
  if (evento.keyCode==69)
  {
  //E
  play_note("E5");
  }
  if (evento.keyCode==82)
  {
  //R
  play_note("F5");
  }
  if (evento.keyCode==84)
  {
  //T
  play_note("G5");
  }
  if (evento.keyCode==89)
  {
  //Y
  play_note("A5");
  }
  if (evento.keyCode==85)
  {
  //U
  play_note("B5");
  }
}
document.onkeydown = manejador;
</SCRIPT>