When lifting, I prefer to listen to something with a steady rhythm. Something with a pretty solid beat where the lyrics (I have a tendency to sing along under my breath if I know the words) won't screw up my breathing cycle. Usually some good hip hop for weight training. Then for running it's all about rock songs with lyrics I do know, although I'm sure I look like a fool cruising on the treadmill mouthing songs. But I keep my cardio music pretty fast paced. It helps me take my mind off the fact that I'm running. Because I hate running. I don't have a runner's build at all.