I'm in agreement with ruinexplorer. There are several royalty free music sights on the web. For the longest time I would use whatever music I felt was appropriate, and slowly got turned on to the free stuff. Much of it is very good, and free due to artists wanting to get their name out there.
I guess for me, being an artist myself, I went with the free stuff because I wouldn't want someone to use my designs freely without consulting me. Just my 2 for you.