Should I send note off for every note on?

I trigger clips in Live using "Note On" messages, but, so far, have not been sending "Note Off" after every "Note On". On rare occasions, I get an error condition in MT, saying that there has been a buffer over-run. I wonder if this could be related to piling up many note on's without sending note off's. I can't pin the error condition down to any particular thing I'm doing in MT.

My thinking for not sending the note offs was this:

  • A clip in Live is triggered (starts playing and keeps playing) when the note on is received. I'm not gating the clip (In which case Live would continue playing the clip only until it got a note off message.
  • The clip continues playing until one of two things happens. -- a different clip is triggered in the same track or -- a command is sent from Live, to stop playback in that track. I suppose Live may be generating its own note off's to stop playback in these cases, but since it's MT that gives me the error condition, I wonder if MT expects note off's to be generated for each note on - eventually.


I see now that this question has been asked before, but not in reference to exactly my situation. Since Live is not complaining, I thought it might be ok to send note on without note off.

For MT Pro, it’s perfectly fine to only send Note On’s and never any corresponding Note Off.

But under normal conditions, it is not OK to see a queue overflow! There are multiple possible queue overruns in MT — Log Window display, or processing queue. The latter might cause discarded MIDI messages in the MIDI stream. It practically only happens when the CPU is maxxed out, or the outgoing processing is blocking, and many MIDI messages come in.
Could you post your project file? What kind of MIDI data is being received by MT Pro? only manual triggers?

Your question about MIDI data being received made me look again at the feedback I input from Ableton, Live and also the fact that I constantly have the log window running as i’m working on my code.
I use the data from Live to gate note-ons in response to fader movement (when the volume fader for a track goes from 0 to a positive value) as well as for other reasons. There’s quite a lot of info coming back from Ableton.
Turning off the log window seems to have prevented these overflows for the past few days. Thanks for the suggestion. Since this was not a common occurrence, I’m not sure I’ve really solved the problem. If not, I’ll get back to you.

By the way… could you please explain the difference between commenting on a post and answering it?