Where can i shop for instrumental (no vocals) songs online?

i need to sing somewhere and i have no accompanist. i havent decided what song to sing, but i wanted to just choose an artist or song and be able to find an instrumental track of that. any possible places online? even a store is fine.

thanks :)

Or perhaps a place to shop for performance tracks? I've tried rhapsody; anything else?

I've bought instrumentals from itunes.com

Try spotlight music, or look up cd&g music. Good Luck!