On one midi instrument track -- in the piano roll editor -- I have discovered that there are actually 7 notes "underneath" each note. Each note in this "stack" is identical in duration and velocity. I can click on a note, drag it down and then the note underneath will show. I can drag that note down further -- and keep doing this until I have done this 7 times. Another way to explain this problem is that if I click on and delete a note, it will still be there -- until I do this 8 times. Then the note is gone.
I have no idea how I created all these notes on top of each other. My problem now is how to delete the 7 extra notes in each note stack. If I select all the notes with the arrow tool, all the underneath notes get selected along with the top note so I can't use delete because it will delete all the notes. But if I just click on one note, I can delete just one note at a time.
I discovered this problem because the track instrument was playing very loudly. But when I deleted a segment of notes and insert recorded a new segment, those new notes played back at much lower (correct) volume. I don't want to play with the gain levels on this track, I want to get rid of the extra 7 notes. I can do this individually but there are many notes in this track. I'm hoping to find an easier way to delete all the extra notes. I would also like to know how I created all these notes so it won't happen again.