I know it's an old topic but I was reading through some of my old posts and wanted to add to what Steve posted above. I will sometimes go into the file as he described to add an individual hit of an instrument where I want it. But, depending on the situation, I sometimes find it quicker to just do some editing in the DAW.

For example, if I want to add a single cymbal hit by itself and no other drums playing, I would go into the file the way Steve described and simply add it to my DAW that way. But let's say BiaB didn't give me a cymbal where I wanted it and the full kit is playing there. Sometimes, I simply find an instance of where the kit is playing with a cymbal I like and copy and paste. It's really about workflow and whichever is easier. BiaB is a powerful tool but BiaB AND your DAW together make the possibilities limitless.

I use BiaB sometimes even on instruments I play and play well simply because I can't match the sound of a $5,000 Gibson mandolin recorded on a world-class board with a world-class mic in a world-class recording studio. I used to fret about "cheating" and think I had to play everything. But I've come to realize the audience cares about how good the song sounds. To me it's no different than bringing in a studio musician for a track.