Alright, need a group-think on this one

I've got a file that says it's an mp3 but it apparently isn't. I'd love to be able to play it, but WMP says the file format isn't what it says it is. How can I find out what the file's true format is?

Puddin' onna RIIIIIZZZZ

Peter Boyle has passed away, folks. :(

In light of this, I'll be running Young Frankenstein this Friday night as the main event of the show.