Especially in certain genres, music can be an important part of the gaming experience. In horror games the immersion can be extremely deep if you employ the right background music. Over the years I have collected various movie or video game soundtracks, classical music, etc. that are suited for this purpose.
While looking for royalty-free music that I can use for a podcast project that never saw the light of day, I stumbled upon Kevin MacLeod’s Incompetech. Over the last few years Kevin has released countless pieces of music that can be used freely under a Creative Commons license. He also created a site with music released as public domain. If you are looking for a piece of music for your game, chances are very high, you find something fitting on Kevin’s sites.
Examples of Kevin’s work:
House of Leaves
All tracks are © Kevin MacLeod, Licensed under Creative Commons: By Attribution 3.0, http://creativecommons.org/licenses/by/3.0/.
For more awesome, royalty-free music check out incompetech.com!