I would want to generate a new sequence of notes of a MIDI file thanks to MusicRNN chord_pitches_improv.
My call to music_rnn.continueSequence triggers the following error:
Uncaught (in promise) Error: Number of splits must evenly divide the axis. at C (music:22) at split_ (music:22) at Module.split (music:22) at t.sampleRnn (music:83) at music:83 at music:22 at t.scopedRun (music:22) at t.tidy (music:22) at Module.$e (music:22) at t. (music:83)
Nothing because I don't even understand the error. Note: I have MuseScore. So If something must be changed in the MIDI file, I can do it.
Download the following MIDI file: https://a.uguu.se/kP1iJ4JVeTrD_b.mid and rename it "b.mid"
Create a directory in which you store the MIDI file
In this same directory, create a file titled index.html: copy/paste in this HTML file the code provided below (section "Sources")
Open your browser and open this HTML file: my script will automatically be executed, and the error will be triggered.
What does this error mean? How could I fix it? Should I change something in the MIDI file (if yes: what? How? Can I use MuseScore to do it?)?
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Music</title>
<script src="https://cdn.jsdelivr.net/npm/@magenta/music"></script>
<script src="https://unpkg.com/@tonejs/midi"></script>
</head>
<body>
<script>
loadMidi = async function() {
const sequence = {'notes': []}
const midi = await Midi.fromUrl("b.mid")
midi.tracks.forEach(track => {
const notes = track.notes
notes.forEach(note => {
if(note.midi < 48) {
note.midi = 48
}
if(note.midi > 83) {
note.midi = 83
}
sequence['notes'].push(
{
pitch: note.midi,
velocity: note.velocity * 100,
startTime: note.time,
endTime: note.time + note.duration
}
)
})
})
try {
const quantizedSequence = mm.sequences.quantizeNoteSequence(sequence, 1)
const improvCheckpoint = 'https://storage.googleapis.com/magentadata/js/checkpoints/music_rnn/chord_pitches_improv'
const music_rnn = new mm.MusicRNN(improvCheckpoint)
const prepareMusic = async() => {
await music_rnn.initialize()
var improvisedMelody = await music_rnn.continueSequence(quantizedSequence, 60, 1.1, ['Bm', 'Bbm', 'Gb7', 'F7', 'Ab', 'Ab7', 'G7', 'Gb7', 'F7', 'Bb7', 'Eb7', 'AM7'])
improvisedMelody.notes.forEach(n => n.velocity = 100)
var midi_bytes_array = mm.sequenceProtoToMidi(improvisedMelody)
saveByteArray("generated_music.midi", midi_bytes_array);
}
prepareMusic()
} catch (error) {
console.error(error)
}
}
loadMidi();
function saveByteArray(reportName, byte) {
var blob = new Blob([byte], {type: "audio/midi"});
var link = document.createElement('a');
link.href = window.URL.createObjectURL(blob);
var fileName = reportName;
link.download = fileName;
link.click();
};
</script>
</body>
</html>
I got same error when I was trying to quantize my note sequence which was already in quantized format. It is worthy to check your note sequence format.