MDL Scratch/Pop Noise, Followed by Glitched Playback

• Jul 4, 2019 - 04:38
Reported version
S3 - Major

Steps: Unknown, seemingly occurs at random.

Expected Behavior: Normal playback when using MDL instruments

Actual Behavior: At a random time at the start of a playback, a loud noise is heard, almost as if a disk is scratching, seemingly comprised of MDL-related noises - perhaps overblown snare buzzes or a similar high-frequency scratch. After this happens, a bug or glitch seems to have 'initiated' in the playback of MDL instruments. Notes begin to accent at random, and others are dropped. This is most noticeable in snare and bass parts, although that could be due to snare volume and bass note density (playing split parts with 16th/32nd notes.)

Workaround: Close MuseScore and reopen. The score playback will now be correct until another scratching noise is heard.

I'm reporting this now because it seems to happen more frequently, but I can recall this happening since at least the first MS3 release. For the record, both MuseScore and the MDL extension are up-to-date version-wise.

As stated, this occurs at random, and seems to happen in any score of any size, so long as there are MDL instruments present. Because of this, I have not included a score but can do so if needed.


Workaround Yes No

This is happening to me too, also in only MS3. MDL is still functional for me in MS 2.3.2. I am also now having problems with the soundfonts themselves, as documented in my own post. I am not sure if these are related occurrences or not.

Where is your volume currently set in Synthesizer? Try reducing the volume in the Synthesizer and mixer and increasing the system volume to return to same volume level.

If not RAM, it could be a volume/clipping issue.

I've just had one of the more apparent instances of this happen after it seemed to stop for a while. This time it seemed to do a bit of a 'build-up' of smaller scratches, followed by a big one that glitched the playback as mentioned above. It might be worth noting that restarting Audio/MIDI devices in the Preferences menu didn't resolve the issue either. I'm still not entirely sure what instances cause the glitch, but from I can recall it happens mostly in scores with two or more MDL instruments; usually a full (3-section) drumline.

Frequency Once Few

I believe that this may stem from the same issue:
I'll add that the scratch noise seems to be composed of every snare drum sound playing at max volume. The "scratch" seems to be mostly a buzz, but there seem to be cymbals, hits, shots, etc. present as well.

I think I understand the issue (related to some changes in SFZ definitions). I will spend time tomorrow working on a fix and see if we can get it out ASAP.

In reply to by Daniel

You can easily replicate the problem with any score that has MDL instruments in it. Start playback and while notes are still playing, press the rewind (or return to beginning) button. You will hear a loud noise, and then the glitch will start playing.

Reproducibility Randomly Always
Type Functional Performance

this has been happening to me ever since i got musescore 3, but as of recently, the tenors have been sounding bad and the whole soundfound bugs out after the loud pop earrapes me. i've played with the synthesizer sounds and i've uninstalled and reinstalled mdl several times as well as resetting musescore to factory settings. i think that this is just a problem with the latest mdl update, mdl 1.3, is there anyway i can go back to mdl 1.2 and downgrade it for a bit and see if the problem goes away????

In reply to by nicolyon1005

Hey Guys, I'm finally back in office after DCI tour. We have made a quick update, please test this and provide feedback so we can quickly adjust and make public release.

To test this, download the latest "nightly" development build:


Once you have installed, go to Extensions Manager and install MDL 1.3.1

Getting feedback on this as quickly as possible will help us to get the fixes and release out ASAP.

In reply to by Daniel

Thanks for coming up with an update! So far the issue of loud popping seems to have gone away on scores with MDL and non MDL instruments. However, the issue of playback seeming not together between instruments still happens occasionally (the glitched playback brought up before I believe). Also, on the development version you linked, crashes still occur occasionally when adding notes or articulations on a score. I'll attach the one I've been using and having that issue with. Thanks!

Attachment Size
Slow_Dancing_In_The_Dark (1).mscz 96.45 KB

I am still experiencing this issue (I have been for a few months now). Is there anyway this can be permanently fixed? It happens when I rewind during playback, but only sometimes.

Reproducibility Randomly Always
Type Functional Performance

I'm still experiencing this issue as well. The loud pop noise is nearly deafening, it scares the living daylight out of me every time it happens and my ears actually physically hurt when it happens. I'll be using Musescore 2 until this is fixed, I can't afford blowing out my ears or blowing a speaker in my headphones or computer.

I have found that the loud noise now occurs exclusively when ending playback, rather than when beginning it, and sometimes the playback can survive multiple occurrences of the scratching noise before it becomes glitched. My workaround of uninstalling and reinstalling MDL now causes musescore to crash sometimes.

Reproducibility Always Randomly

Any update on this? Getting pretty frustrated with constantly having to close and re-open musescore. The MDL extension isn't even worth using right now, given the frequency of this bug for me.

When the bug occurs, it can be fixed without restarting the software by shifting at least one instrument under the 'Zerberus' tab in the Synthesizer. However, this causes the entire index to be reloaded, and takes almost the same time as restarting Musescore.

Any chance we can have some form of update on this? Even just tell us ,"we're not sure what's causing the issue, so make do while we look into it," but this has been happening (really, since release) almost a year now...

Reported version 3.2 3.6

I have a big project I've been working on now and it's to the point where I have to close it every few minutes of so this is almost unworkable. Please bump.