I jam all kinds of music, Mostly Female Country, Teen Pop, and Dance music. I let iTunes build a seriously random playlist of highly rated songs for my 40gb iPod. Its connected via a cassette adapter. I generally keep the volume at about 40 out of 60 on the Prius JBL 9-speaker system. When a really awesome tune comes on, I crank it up to near max, but I generally turn it down after the song is done. It Rocks! My other settings are a the default, the treble might be tweaked up a little, but thats about it. Since I put about 2 hours/day into driving, music is the only thing that keeps my sanity! I also have a backup of some of my favorite songs on 3 CD's just in case something happens to my iPod!