Take a look at Read MP3 Property Info Thread #671272.

>i have my music collection on wma and mp3 now and am happy with it but when i started doing this years ago i had a naming convention, but thats all gone to pot since i started using mediaplayer. its great in that it gets information from the web about my songs but i want to change the actual file names without having to manually do it or resave them through media player. inside the files all of the relevant information is stored as i had a look at it in notepad but i don't know how to get this information out, has anyone any ideas.