Here’s my MIDI software synth Bawami doing its best to even keep responding while trying to play TheSuperMarioBros2‘s black MIDI “Arecibo“. The left view shows how it’s processing every MIDI message. Not shown: About 5 minutes of Bawami loading the 12MB MIDI file hideously inefficiently (tempo changes make it even worse).
This problem of my player stopping responding when maxed out is something I need to (re-)fix. I fixed this a long time ago (probably before releasing Bawami), but broke it again afterwards somehow, also a long time ago now… As always, the most recent version of Bawami can be download here (also check the most recently tagged posts to see recent changes).
TheSuperMarioBros2 have made a lot of great black MIDIs that are often fun to stress-test MIDI players with. You can see lots playing at their channel (they also provide download links for the MIDI files). However, Bawami’s loading of MIDIs is inefficient, so I’d recommend not trying to torture it with black MIDIs too much. I also suggest unticking “Loop” so that, if it stops responding during playback, it’ll eventually start responding again at the end.