While scouring the web recently, I came across the website for Soundation, an online music production tool.
The tool works much like other multi-track editing programs, but is first of all, Free, and second provides a number of samples for you to use in building your music files.
Of course there are options to buy more samples than the free ones offered, but you could build a pretty good creative open, credit sequence, or segue track for your show, with just the free samples.
Also, as far as copyright conditions are concerned, basically you can keep and use any composition you make without restrictions, but you can’t reproduce the music samples as individual files for sale or library production (please don’t consider this a full digest of the terms and conditions).
I say check it out.