In the post Adam mentions a couple places he likes to go to find license-free music for his projects. If you can’t create the music yourself or find someone who can, these are good options:
I still stick by Jamendo as the place to go to get licence free, quality music for your productions. The quality of the music is high, but it will take a long time to find that perfect piece (my advice: only search for the French musicians!)
There is, however, a challenger in town…
Works in much the same way as Jamendo, utilizing a community of amateur music producers to create a whole array of sounds for multimedia types. The difference is that Humtoo seems to aim itself more at the professional media market, with clients including ITV and Current TV. It also has a forum where producers can request the types of music they want.
Music for broadcast is royalty free…but for everything else, it seems you might have to negotiate.