What Ethan Said:
The audio clips come via Shutterstock’s partner, Rumblefish.Not sure what this has to do with us or creative individuals.
http://www.rumblefish.com/music-catalog.php"Rumblefish is always looking for the best new music to license. If you own and/or represent an amazing catalog with a track record, please reach out. The basic criteria are a sizeable artist roster, both master and publishing rights available worldwide, an artist-friendly reputation and a proactive approach to collaborating. The goal is to meaningfully increase sync licensing revenues for you and your catalog artists."
I don't think it's single files right now. At least that's the way it looks?