Can't change instrument in Java MIDI program, InvalidMidiDataException:channel out of range

Question

I can't change instrument with javax.sound.midi.ShortMessage.setMessage() method. Channel 0-15 is piano, excluding 9 which is for drum. But 8-15 should be Chromatic Percussion. When i set channel to 16 or more (range is from 0 to 127), i get javax.sound.midi.InvalidMidiDataException: channel out of range: 16. Please, How can i fix this?

    import javax.sound.midi.*;

public class TestMidi{

    public void play(){
        try{
            Sequencer player = MidiSystem.getSequencer();
            System.out.println("Sequencer created succesfully.");

            player.open();

            Sequence s = new Sequence(Sequence.PPQ, 4);

            Track track = s.createTrack();

            addShortMessage(track,1,192,1,102,0);
            addShortMessage(track,1,144,1,44,100);
            addShortMessage(track,16,128,1,44,100);

            player.setSequence(s);

            player.start();

        } catch(Exception e){
            System.out.println("Fail.");
            e.printStackTrace();
        }
    }

    public static void main(String[] args)  {
        TestMidi tm = new TestMidi();
        tm.play();
    }

    void addShortMessage(Track track, long tick, int command, int channel, int data1, int data2) throws Exception {
        ShortMessage msg = new ShortMessage(command, channel, data1, data2);
        MidiEvent event = new MidiEvent(msg, tick);
        track.add(event);
    }
}

A MIDI port has 16 channels, 0…15. Why do you think there are more? — CL., Mar 05 '20 at 09:43
Well, I read an example in a book Head First Java (second edition). In example, there was numbers like 102, 80, 40. Also, on this website [link](https://www.midi.org/specifications/item/gm-level-1-sound-set) i found a table named **General MIDI Level 1 Instrument Families**. — Alex Kadushkin, Mar 06 '20 at 05:47
I figured out that channel is representing an instrument, right? — Alex Kadushkin, Mar 06 '20 at 05:54
There are 16 channels. Each channels can have its own instrument (by sending a Program Change message). Usually, each channel can play multiple notes simulteneously. — CL., Mar 06 '20 at 09:51
@CL I added 'a.setMessage(192,1,102,0);' in code. Why does it still play piano? — Alex Kadushkin, Mar 08 '20 at 10:18
@CL In all other methods setMessage changed channel to 1. Idk, how to insert code here. — Alex Kadushkin, Mar 08 '20 at 10:21
@ CL, yeah, sorry, i meant the value 1 which is the second channel — Alex Kadushkin, Mar 09 '20 at 09:24
A call to `setMessage` is not enough; you have to add three messages to the track. — CL., Mar 09 '20 at 10:10
@CL could you be more specific, please? what are the messages to the track? — Alex Kadushkin, Mar 10 '20 at 17:21
@CL idk how to insert code here. Comment section is too small. — Alex Kadushkin, Mar 11 '20 at 18:34

score 1 · Accepted Answer · edited Mar 15 '20 at 00:54

1

Channel numbers go from 0 to 15. Each channel can have its own instrument (by sending a Program Change message).

This code adds two messages to the track. If you want to add a third message, you have to call track.add() with a third object.

Adding events would be easier with a helper function like this:

void addShortMessage(Track track, long tick,
                     int command, int channel, int data1, int data2) {
    ShortMessage msg = new ShortMessage(command, channel, data1, data2);
    MidiEvent event = new MidiEvent(msg, tick); //edited here
    track.add(event);
}

edited Mar 15 '20 at 00:54

Alex Kadushkin

35
6

answered Mar 13 '20 at 20:33

CL.

173,858
17
217
259

idk why, but it started working, maybe there was something with my software or it was just so silent. Anyway thank you – Alex Kadushkin Mar 20 '20 at 19:07

Can't change instrument in Java MIDI program, InvalidMidiDataException:channel out of range

1 Answers1