Google Colab - stream.show('midi') only plays piano

[samuel-1184]

music21 version

9.9.1

Operating System(s) checked
Mac 26

Problem summary

When playing midi file in Colab, only piano soundfont is being used.

Steps to reproduce

Run this code in colab, and click the play button, you'll hear piano sound:

from music21 import converter, instrument
stream = converter.parse('tinyNotation: 4/4 C4 D4 E4 F4 G4 A4 B4 c4')
stream.insert(0, instrument.Accordion())
stream.show('midi')

But using play_midi you'll hear accordion:

from midi_player import MIDIPlayer


from music21 import converter, instrument
stream = converter.parse('tinyNotation: 4/4 C4 D4 E4 F4 G4 A4 B4 c4')
stream.insert(0, instrument.Accordion())
stream.write('midi',fp='/tmp/music-51.midi')

MIDIPlayer('/tmp/music-51.midi', 400)

Expected vs. actual behavior

More information

I could see the grand piano ogg being downloaded, but not others.

Thanks for your work and help!

[mscuthbert]

Thanks Samuel for the bug report -- this is a known limitation of using Music21 in Google Colab -- I've not been able to figure out a fix for this. I should find a place to document the use of Music21 in Colab somewhere... I know that it's under documented.

I'm afraid this is unlikely to be fixed by me soon since I'm not teaching regularly with Colab these days. But glad to see patches and suggestions. An upgrade to the newest music21j on the music21 backend would probably fix everything...

[samuel-1184]

Thanks Cuthbert for your reply! One thing I'd like to add is that this issue is not Colab specific. I first encountered this issue in Dataphi, yet another collaborated notebook service. Therefore both Dataphi and Colab have this issue. I haven't tried in Jupyter Lab but I suspect this will repro as well.

Again, thanks for making all this happen. Best wishes.

[mscuthbert]

Got it -- they all use some of the same code underlying (from iPython/Jupyter originally before they're all forked), but they implement CORS etc. differently.