Change pitch of the note currently played

[avf]

Thanks for creating this awesome library!

I have a digital piano connected and I'd like to dynamically change the pitches of the notes being played. I'd like the sound of the changed notes to come from the piano speakers. So for example, transpose all notes being played on the piano by an octave up.

I've attempted to do this by adding a listener, and forwarding the note to the output on the piano, but of course that just results in both notes being played at the same time:

const output = WebMidi.outputs[0]; // same device
const input = WebMidi.inputs[0]; // same device
input.addListener('noteon', (e) => {
    output.sendAllSoundOff();
    const pitchChange = 4;
    output.channels[1].playNote(e.note.number + pitchChange, {duration: 100});
});

I'm assuming that output.sendAllSoundOff(); doesn't actually do anything here, because the sound of the original, unaltered note is actually coming from the input, not the output.

Is there a way to suppress the original sound from the piano, and only play the sound on the output? Or is there another way to achieve what I'm trying to do?

[takyano]

Does your digital piano have an option called LOCAL OFF?

Brand and model of the digital piano would be helpful.

[avf]

Thanks for the quick response!

Unfortunately, my Yamaha P-45 doesn't allow Local Control to be turned off, according to the manual (p18).

However, I found this forum post that says you can still turn it off by sending some specific control change events. Is this something I can try easily with WebMidi or do I need to drop down to the native API?

[avf]

Ah, I just realized, there's a sendLocalControl message API.

This works, I'm quite happy :)

const output = WebMidi.outputs[0]; // same device
const input = WebMidi.inputs[0]; // same device
output.sendLocalControl(false);
input.addListener('noteon', (e) => {
    const pitchChange = 4;
    output.channels[1].playNote(e.note.number + pitchChange, {duration: 100});
});

Still needs a few tweaks, such as using sendNoteOn instead of playNote, and forwarding the correct attack and release, but it's a working proof of concept.