Jonathan E. Brickman wrote: No, Jonathan, unfortunately I didn't check... was running behind schedule before the gig, and haven't been near my system since. It may take a while for me to get back to my system, and checking CPU load will be the first thing I intend to do. Couple of other things that I missed out in previous posts. Firstly, before the gig I wanted to check whether it was a qsynth-specific or general fluidsynth issue, so I installed ghostess, which can run multiple instances simultaneously. I loaded the same soundfonts, and experienced exactly the same issue - so if there's a bug in the app, then it must be in the fluidsynth libraries. Second issue of note: few weeks ago, while still running Ubuntu, I wanted to find out what exactly caused the jack crash that I reported on this list at the time (perhaps unrelated to the current issue) . I found a "stress test" to replicate the problem: hitting a lot of notes while keeping my sustain pedal down. Initially, the crash would happen within 20-30 seconds of banging the controller (!). When I changed the polyphony settings from 256 to 64, it would be much more stable - for more than 10-15 mins of banging! Again, I was able to replicate the same thing with ghostess. This incident has left me with a lurking suspicion about a possible bug in the fluidsynth libraries. I'm curious, though... has anyone else experienced similar issues? Looking forward to pointers/feedback/suggestions. Cheers, Guru