There are so many examples of midi "single-sample" drums. I especially like the second:
http://www.youtube.com/watch?v=SpthXkSAw2Ehttp://www.youtube.com/watch?v=iXkS8xSabaMNow you could store e.g. 8 or 16 bars of what the drummer plays as a conventional midi style drum part variation. AND later you could change every single note. No need for audio.