MIDI Channel Assignment missing in MuseScore 4

• Dec 21, 2022 - 22:04
Reported version
S3 - Major
GitHub issue

In MuseScore 3, the Mixer comprised functionality to assign MIDI Ports and Channels as well as Reverb and Chorus to a certain instrument. This functionality is seemingly missing in MuseScore 4. When playing a score with more than one MIDI instrument, every note is sent to all instruments, which makes MIDI playback unusable.
Example attached.

Attachment Size
C8 V2.mscz 23.13 KB


Frequency Once Many
Status active needs info

Yes, this is a known limitation. It remains to be seen if that functionality will be returning in a future update or not. However, I am not understanding what you mean about information being sent on all channels. That should not be the case. Can you explain in more detail what specific problem you are encountering that would require an explicit channel assignment to fix? Are you trying to connect to a DAW, or to a physical MIDI synthesizer? Is you device set to single, multi, or omni modes?

In reply to by Marc Sabatella

I created a score with 3 instruments, each of which is a physical synthesizer with dedicated MIDI channels 1, 2 and 3 (see example attached to the ticket). Of course I want only the notes of the staff of a certain instrument to be sent to this instrument and not to the other two. In MuseScore 4, the notes of all three staves are sent to every instruments, which results in chaos.

The synths only support dedicated MIDI channels and normally don't respond to other channels. There is no possibility to change between single or omni mode.

I was looking how to use vst3 software instruments. It seems to be that all staves in a score use MIDI channel 1 to send notes to VST3 software instruments. So there are parallel and separate MIDI channel 1 streams, as many as there are staves in the score. This works OK with software vst3 instruments.

Obviously this doesn't work OK with external hardware synths. I suppose the parallel and separate MIDI channel 1 streams are no longer separate after they have passed through a MIDI cable. But the synths should give no sound on other than channel 1. If they play no matter what channel they are set to receive, then the MIDI channel number gets lost somewhere or gets converted to omni.

I made also further tests and have to correct myself. My first impression, that the notes are sent to all devices was wrong. In fact, only MIDI device 1 is active. Since this is polyphonic, notes form all three staves where played in parallel on that instrument, which led me to the wrong impression (the outputs of the synths are mixed together).
Anyway, there is no proper distribution of the staves to the corresponding instruments. If I set all three synths to MIDI channel 1, they really play the notes of all staves on every instrument. Reconfiguration to the channels 1, 2 and 3 in the instruments returns to the initial problem.
Isn't it possible to re-implement the simple MIDI channel selection feature for each instrument in MuseScore 4?

The MIDI channel selection is a must, I agree.

I think the mixer should have signal router capabilities. It acts as a switch box between the score and the instruments, connecting each score staff to some instrument. It should make possible to change the midi channel, let one staff drive several instruments (including MS Basic, Muse Sound, VST3), let several staves drive the same instrument (multitimbral, multichannel) and build effect chains (FX - instrument, many FX - one instrument, one FX - many instruments).

Absence of MIDI out channel selection for each stave in MuseScore 4 is the only reason I still have to stick with Sibelius.

It is crazy that they released MuseScore 4 with less functionality than MusesScore 3. At least they should add an "Save as MuseScore 3" option to go back to MS3!! I converted some scores to v4, created some new, but I'd go back to v3. Too many issues in MS4. Really sad.

MuseScore 4 does have more functionality than 3 am/ lots of new things added. But some things didn’t make the transition indeed. If they waited until literally everything was ported, we’d still all be waiting, instead of enjoy the new improvements today. Meanwhile you can of course continue using MU3 if you prefer not to enjoy the improvements today. If you wish to open an MU4 score in MU3, export it to MusicXML.

I arrange for my blues band's horn section. I tried using the new Muse sounds, but the trombone was SO low that it was pretty much useless. So instead, I used my VST3 Chris Hein Horns (Kontakt 7). And now this issue has popped up - since it's all on the same MIDI channel, when the horns do a unison part the volume drops down considerably.

I'm glad this thread was started - perhaps they will be able to "fix" this missing option. There are some really nice improvements in version 4, but this is big problem if you want to hear a decent preview of what it will sound like. BTW - anyone know how to fix that issue with the trombone? Aside from jamming the volume all the way up, which still doesn't provide the right volume against a tenor and trumpet?

In MuseScore 3, the Mixer comprised functionality to assign MIDI Ports and Channels as well as Reverb and Chorus to a certain instrument. This functionality is seemingly still missing in MuseScore 4.1 Update.

Workaround No Yes

I was able to work around this problem by exporting my Musescore 4 file to an XML file, and then open the XML file in Musescore 3. I could then assign the midi channels. I almost started to rewrite my song in Musescore 3, luckily the XML file saved me. :)

MIDI channel assignment / control is a vital feature for MIDIs played back on any modern digital keyboard. The channel selection buttons on a digital keyboard become useless if the MIDI file lumps all notes into one channel!

If I may ask, please put this feature back into Musescore at the earliest opportunity.