One of the more entertaining chapters in Alex Hutchinson's book, Which Comes First, Cardio or Weights?
is his chapter on the effect of music on athletic performance. There actually is some evidence that listening to music while exercising can reduce the level of perceived exertion, and therefore help you go longer/lift heavier/whatever. What I found particularly interesting was that different types of music were better for different activities: for aerobic activities such as running or biking, a steady, fast beat was most beneficial to performance, whereas for weight lifting, "motivational lyrics" seemed to have the most effect.
I have a couple of playlists for running, and a playlist for weightlifting. I even have a kind of a playlist for climbing - you can't really use an iPod while climbing, but I often hear music in my head when I'm on a particularly tricky bit of wall. (Once in a while, Planet Granite obliges me by playing one of my climbing songs outside my head.) Climbing songs have a lot in common with weightlifting songs, except that they have a statistically significant lyrical focus on climbing, falling, or vertical movement, and are generally selected based on the Hollywood movie soundtrack principle that any death-defying move done to the accompaniment of a sufficiently badass guitar riff has to succeed.
So, I thought it would be fun to post a song from each of my playlists.
Running song: "I Ran" by Flock of Seagulls. I think you are required to have this on your iPod if you run.
Weightlifting song: You get bonus core work from trying not to laugh at the lyrics. "I'm Sexy and I Know It" by LMFAO.
Climbing song: "Do Not Look Down" by Meshuggah.
Do have a favorite workout song? Post a link in the comments.