Just what it says above. All I've ever tried to do when listening for a part is to use the iTunes equalizer to bring up the bass part. It occurred to me there might very well be software out there that isolates the various parts even better. Does anyone know of anything?
Thanks so much! In the meantime I tried out Audacity just for slowing down a part while I learned it and immediately loved that aspect of it. I'm going to check out the other stuff that was recommended. Keep any tips coming if you got 'em!