MIDI

Sound`MIDISequenceToBytes[
 Sound`MIDISequence[{Sound`MIDITrack[{Sound`MIDIEvent[0, "SetTempo",
      "Tempo" -> 1000000],
     Sound`MIDIEvent[0, "ProgramCommand", "Channel" -> 0,
      "Value" -> 11],
     Sound`MIDIEvent[0, "NoteOn", "Note" -> 60, "Channel" -> 0,
      "Velocity" -> 127],
     Sound`MIDIEvent[0, "NoteOn", "Note" -> 64, "Channel" -> 0,
      "Velocity" -> 127],
     Sound`MIDIEvent[0, "NoteOn", "Note" -> 67, "Channel" -> 0,
      "Velocity" -> 127],
     Sound`MIDIEvent[0, "NoteOn", "Note" -> 72, "Channel" -> 0,
      "Velocity" -> 127],
     Sound`MIDIEvent[480, "NoteOff", "Note" -> 60, "Channel" -> 0,
      "Velocity" -> 0],
     Sound`MIDIEvent[480, "NoteOff", "Note" -> 64, "Channel" -> 0,
      "Velocity" -> 0],
     Sound`MIDIEvent[480, "NoteOff", "Note" -> 67, "Channel" -> 0,
      "Velocity" -> 0],
     Sound`MIDIEvent[480, "NoteOff", "Note" -> 72, "Channel" -> 0,
      "Velocity" -> 0]}]}, "DivisionType" -> "PPQ",
  "Resolution" -> 48]]