Did something interesting in a track that I'm about to post soon... I wanted a bass track where every note would have a somewhat different timbre. I generated six scales (C to C) of bass notes using six different patches in Csound, and imported the whole Csound output AIFF file into a Metro audio track. Then, I started copying bits of various notes and pasting them into the song (a la an old-fashioned tape studio, except no razor blades ).
This of course caused some of the notes to have pops at the beginning and/or ending, since I was copying from the middles of the generated notes. I got the idea of using the audio fade in/out commands (in the Edit menu) to fade in/out over a few cycles to get rid of the pops. Then, it occurred to me that by overlaying fades of various lengths, I could create some complex envelopes on some of the notes. It came out pretty cool.