'Loop Playback' won't stop (space or play just invokes playing from start point)

• Aug 11, 2020 - 19:20
Reported version
S4 - Minor

In certain scores, when selecting 'Loop Playback' mode and pressing play (or space bar) to play, consecutive presses of play button or space bar do NOT stop playback, but instead this invokes playing the loop again from its start point. The play button indicator does cycle its graphic, but playback can only be stopped by disabling 'Loop Playback' mode and pressing the start/space bar at least once or twice.

Steps to recreate, using the attached file:

1) Open the file and select measures 17-40.
2) Invoke the 'Loop Playback' mode with the button at the top.
3) Click off the highlighted measures and press play (while still in 'Loop Playback' mode.

Only seems to happen with certain project files, but I'm not the first one to see the issue. Bug discussed and verified reproducible in the following forum post (which I did not create):


Reproducible in both of these versions:

  1. Windows version: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit):, revision: 43c5553
  2. OS: macOS 10.15, Arch.: x86_64, MuseScore version (64-bit):, revision: 43c5553

Please don't hesitate to send along any questions or if I may be of further assistance. Thanks a lot. -Alan


I've seen similar problems with playback but I don't use loops. I start playback, press the space and it seems to jump back to the start spot as though I've pressed the space bar twice. I think I have to use the mouse and click the stop button to stop playback.

If it makes a difference, I use page view.

Ok, I am the OP for this thread.


I eventually tracked down the problem (I think). If you have the "Play Repeats" button highlighted (in the main playback panel), and if the loop has repeats anyway (??), it won't stop playback via the space bar or the play panel. Only way out is to unclick looping, click outside the loop and stop then.

The problem goes away if the "Play Repeats" button is unhighlighted. If you highlight and hit play the problem comes back, but NOT the first time, the second time (??). Weird

There seems to be more to it than that, though, as I could not reproduce this from scratch in a different score. I tried adding repeats around the first two bars, selecting another bar, turning on both repeats and loop, and everything worked as expected. Well, except for one thing that might be a clue - when the end of the loop is reached, the playback cursor briefly flashes back to the measure after the end repeat.

In reply to by Timborino

Thanks for the post. I would still have to suggest that this is a bug (and should be fixed). There's no reason why toggling playback should restart it instead. Additionally, I'd looped the very same section before updating to 3.5 and the problem did not occur there. Whatever the dependency may be, I'm hoping this can be fixed.

It's absolutely it's a bug, even if we still don't understand what causes. But disabling the repeat button does seem to be a workaround for at least some cases.

In reply to by Jojo-Schmitz

I have the same issue. I can't find a logical way to reproduce but it often happens and is pretty annoying. When it happens I haven't found a way to stop playback other clicking a bit on all options of the playpanel until MuseScore finally accepts to stop playing. I never had that issue with MuseScore 2.

(By Google Translate)
I experienced the same problem. I created a sample, so please have a look.
1) Open sample 1, sample 2 and sample 3 at the same time.
(Samples 2 and 3 are for investigating the problem.)
2) Set the loop from the 5th bar to the 8th bar of sample 1.
3) Click the play / stop icon to start playback.
4) Click the play / stop icon. do not stop.
(If it stops gracefully, do the same with sample 2. You will have problems. Then you will have problems with sample 1. Sample 3 will not.)

Attachment Size
sample_1.mscz 4.28 KB
sample_2.mscz 4.16 KB
sample_3.mscz 4.09 KB

In reply to by yamada_y

Another case that the problem occurs.
1) Open sample 4 and sample 5 at the same time.
2) Set the loop from the 5th (or 6th or 7th) bar of sample 4 to the 8th (or 6th or 7th) bar.
3) Click the play / stop icon to start playback.
4) Click the play / stop icon. do not stop.
(If it stops normally, move to sample 5 and then go back to sample 4 and do the same operation. The problem occurs. The problem does not occur with sample 5.)

Attachment Size
sample_4.mscz 6.06 KB
sample_5.mscz 6.03 KB
Frequency Few Many
Status active PR created
Reported version 3.5 3.6

Same problem after installing. Cannot stop play once in Loopback, unless loopback is disabled.
OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit):, revision: 3224f34

Please attach your score as well. So far we don't understand the reason some scores exhibit this behavior, so more samples may help us identify whatever it is they have in common that is triggering this bug.

Reported version 3.5 3.6

OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit):, revision: 3224f34

I'm experiencing this same infinite looping issue with the attached score.

To replicate the issue:
1. Highlight (almost) any bars. I found it consistently with bars 31 through 39 selected
2. Enable Loop Playback and Play Repeats (screenshot attached)
3. Press Play with the mouse or spacebar, both have the same effect
4. Try to stop the playback with mouse or spacebar
5. The playback jumps back to the first bar and starts over

The playback button un-highlights as though it should have stopped, but the midi is still playing from the beginning of the selected loop

To escape the playback loop you have to use the mouse to disable Loop Playback or Play Repeats and then press the Play button twice to stop.

I tried to investigate the problem and hopefully have found some clues. I like to explain the behavior using my score O Pato: https://musescore.com/user/30027544/scores/6694192
It would be nice if you try to reproduce my findings.

1: Press buttons Toggle Loop Playback, Play Repeats, Pan Score Automatically
2: Mark bars 6 to 8 and press Space (playback starts), Esc stops => ok
3 a: Press Space (playback starts, Playback Button is pressed)
3 b: Press Space again (blayback restarts, Playback Button gets unpressed)
3 c: Press Esc (now it does not stop playback, it's without function) => bug
3 d: Press Space again (blayback restarts, Playback Button is pressed agin) => Esc stops playback like intended.
4: Unpress button Play Repeats and make same tests. All works well.

Seems that it happens in repeats when the Play Repeats button is pressed.
I hope you can reproduce said behavior and it gives a clue what happens.

BTW: I'm on version under Linux Mint 20.1 64 bit. I have never seen the same behavior in version 3.5 and I often used this functionallity.

This failure didn't happen to me for a score I wrote from scratch in Version 3.6.2 but happens in scores that I had started in Version 2.3.2 or earlier and for which I accepted the three suggested improvements when I brought them into Version 3.6.2 for further work.

In reply to by IWillPlayGreat

Yes but that is just random.
Well no it can't be "random" but there is no link with version.
It happens for me for scores created in 3.6.2, sometimes yes sometimes no.
I can't find a way to reproduce systematically, only pattern I "feel" is that the playback limits must be in repeat signs for the issue to occur.

Although I've never been able to intentionally replicate this issue, over Zoom, I've seen literally all of my students encounter it. And about half of them have intermittent problems with delay when playback tries to return to the start of the loop. (I have them all on alert looking for steps to replicate.)