Custom Instruments Do Not Play Sounds

• Mar 26, 2023 - 18:04

Prior to MuseScore 4 I used custom instruments.

MuseScore 4 sorta changed the way it applied custom instruments. It appears to read it via the Edit :: Preferences :: Score :: Score order list 2.

MuseScore will load my instruments, and correctly apply the visual elements. E.g., string data. But it will not play any tones for my instrument. MuseScore is not applying the definition.

I believe muse score is deferring to some pre-defined channel assignment mapping as described in this file.…

I tested this by editing the instruments.xml file deployed with the MuseScore4 install. I changed the Kazoo channel assignment from 85 to 25. This should have switched it from "Solo Vox" to "Guitar". (The XML comments indicate that both voices default to bank 0.)

I restarted MuseScore 4, and used the Kazoo instrument. Muse score continued to use the pre-defined channel "Solo Vox".

So - short problem description - MuseScore 4 does not correctly read and apply instrument definitions read either from the instruments.xml file deployed with the install, nor does it correctly read custom instrument definition files.

I've attached the instruments XML file that I've modified at line 9859.

Attachment Size
instruments.xml 676.54 KB


In reply to by Jojo-Schmitz

What is the solution? Did Mu4 simply drop the ability to create custom tunings?

It seems like Mu4 created better work flows for common issues like this, so I'm thinking that there is some way to address this scenario.

Below is my current work around.


MuseScore does read the string data from the XML custom instruments file, but plays back the MIDI patches defined in another file -- maybe the binaries deployed under the Sound folder.

To trick a custom instrument into playing back sound it will need to appropriate the MIDI assignment of another instrument by assuming it's instrument id.

Search this list for an instrument with the desired timbre, but also note its genre and group.  These two attributes will determine which instrument filter will display the custom instrument.  E.g., group=plucked.strings, genre=common will display the instrument under the *common **plucked strings* category.

For backward compatibility with existing scores be sure to use the same LongName.

Also add the and definitions.  The TrackName defines how the custom instrument lists in the Instruments selection menu.

Add a definition to document what the instrument is.  This will display during instrument selection.

If the default instrument transposes the clef of the instrument, then override that value by explicitly defining the attribute.  

E.g., G

In reply to by mrbbolt

I've come across the same hurdle in attempting to add custom instruments, so thank you for posting your workaround! I'm wondering what exactly you mean by "assuming" another instrument's id to grab its MIDI assignment. Are you simply giving your custom instruments the same id as a default instrument instance?

I'm asking because I don't want to override any default instrument settings by adding these new instruments. My custom instruments have purposefully limited pitch, and I'm worried that that will apply to the original instrument as well if I don't assign them unique ids.

In reply to by Mathiross

has anyone made more progress on this? I have been working on something that has "Tremelo strings 8vb" as a synth patch and I was hoping to just copy the default "strings" grand staff instrument, add an octave transposition. and delete the arco and pizz channels. Its in the instrument list now, and it does show eg C4(sounding like C3) when you enter notes, nut there is no playback at all. It would be handy

Do you still have an unanswered question? Please log in first to post your question.