Free Copyright free music? Please Help!?

For my media coursework we are producing an opening of a film and we need to find copyright free background music. I have already looked at some copyright-free sites but you have to pay. I want instrumental music not a song with lyrics - i'm doing a psychological film so it would have to be something like mystery type music. Also, does anyone know (where on the internet) you can find a loud clock chiming sound and the sound of gunshots. It would be GREAT if you could answers my questions and I would really very much appreciate it! Once again thanks.