no, overlapping notes may are perfectly possible--how could it be with playing chords if it wouldn't?
what I'm talking about note events with zero-duration, in standard MIDI this is a Note-On followed immediately by a Note-Off message or without a least reasonable time interval; it's quite hard to detect this visually on the piano-roll, as an extremely narrow rectangle if visible at all; but you can certainly see them at the MIDI editor's View > Windows > Events listing: notes with plain zero duration.
no, overlapping notes may are perfectly possible--how could it be with playing chords if it wouldn't?
what I'm talking about note events with zero-duration, in standard MIDI this is a Note-On followed immediately by a Note-Off message or without a least reasonable time interval; it's quite hard to detect this visually on the piano-roll, as an extremely narrow rectangle if visible at all; but you can certainly see them at the MIDI editor's View > Windows > Events listing: notes with plain zero duration.
byee