Find out which music is bought on iTunes or imported from CD

Hey everybody,
If say - someone I knew had used my laptop to download things from an illegal source, but I actually wanted to get rid of any of the music they downloaded illegally and replace it with iTunes purchases!
Also, they imported some things off CDs that I had purchased but I don't know which ones are from legal CDs and illegal downloads.

Is there anyway of finding out which thing is which so I can pay for the music that I love and give the artists what they deserve?

If you right click on any song you'll get an 'get info' option on the list. Click that and you should be at the summary page which will give you info about that song.

If it was an illegal download it will most probably be in mp3 format or mpeg audio, if it was ripped from cd in itunes it will probably be in AAC format. There will also be some information on how it was encoded, and whether it was from itunes or not.

Hey Danny, thanks for the reply - I'll try to go through all the different things in the library and try to work out which is which. I knew I'd have an awkward niggly kind of problem.
Thank you anyways, will trawl through to see if I can help out now, be a bit more active...