Portamento glissandi non-functional in Muse Sounds

Issue type

Muse Sounds bug

Bug description

@bkunda update from 1July24: some Muse Sounds instruments do trigger "portamento" style glissando samples, whereas others do not. See my comment below.

It seems that portamento for glissandi is no longer functioning in Muse Sounds, apparently broken with one of the recent Muse Sampler updates. I know in the past that portamento was only supported where it was specifically sampled, but it seems that currently it just isn't supported at all - at least I can't find any examples where it does work for woodwinds or brass

Steps to reproduce

1. Create score for Bb clarinet, key of C concert (D major transposed)
2. Add two half notes, D5 F#5
3. Add glissando, set to portameno playback
4. Play

Result: no gliss at all

In other cases, the second note is also delayed, or even not played at all.

I have tried lots of different notes, also lots of different instruments. I can't find any that work, although of course I haven't tried everything. But MS Basic works fine.

Screenshots/Screen recordings

no-portamento.webm

MuseScore Version

OS: Debian GNU/Linux 11 (bullseye), Arch.: x86_64, MuseScore version (64-bit): 4.2.1-240090504, revision: github-musescore-musescore-45f916e

Regression

Yes, this used to work in a previous version of MuseScore 4.x

Operating system

Debian 11

Additional context

I can't prove these specific notes worked previously, but I know some did, and right now I can't find any that do. Except solo strings, which pretty much always have some portamento anyhow so it's hard to say for sure.

Wish I knew for sure of a specific case that used to work to test. The case here doesn't work in 4.1.1 either but I assume it's really about the Muse Sampler version, not the MuseScore version. I'm currently on 0.5.1.61