Here are some tips on selecting music for fireworks shows.
With FWsim, you can create sophisticated fireworks with music. You can create HD videos from your shows and upload them to YouTube.
Here are some links to free music sites.
On CCMixter, you will find remixes; all licensed under Creative Commons. There are lots of different genres. You might have to search a while to find music suitable for fireworks shows.
OCRemix.org is a community of people who remix video game music. Many tracks there will work well with fireworks.
Similar to Jamendo, the Free Music Archive offers music in a wide variety of genres.
IMSLP collects classical music recordings. Click the link above to get a list of all recordings by composer.