I'm working on a Raspberry Pi project at the moment and I'm searching for a possibility to play a note as long as ey press a button (connected with gpio). 
I use pyFluidsynth and got it working but it's note holding a note as long as i press a button, it repeats it really fast but to slow not to hear it.
Is there any control I don't know? I'm just using noteon and noteoff, is there maybe something like "notehold"?
thanks!
In MIDI if you send a note on message it stays on until you send a note off. Maybe you are sending a note on every time you check the state of the button? If so, you shouldn't, send the note on/note off only when the button state changes.
How to play a note as long as I hit the key (Fluidsynth)?