Are you looking for soundtrakcs, whole music albums, NOT in MP3 format, but just like your CD?
That's easy, and for any music you like, Jazz, Classical, Folk, World, Rock, etc.
The main point is that you are looking for an UNCOMPRESSED file format, or more preicisely a LOSSLESS format, meaning that you'll be able to rebuild the original CD, without losing a bit of information, NOT like MP3 or MP4 etc. Lossless.
You can find that on USENET, sometime called "NEWS". USENET is an ancestor of Internet, which exists since the beginning of computer networks, and before the Internet. On USENET people posts files that are mirrored on all the USENET servers.
Yo can search USENET just as you search the internet, you just need the right search engine! Since USENET is normally for discussions in forums, called newsgroups, in text form, you can use Google to search, just go to http://groups.googlc.com.
But actually, what you're looking for is music. Music is not text, CD are in binary, so they are avalaible in "binaries" newsgroups, which contains the word "binary" in their name.
So, let's say you're looking for Deep Purple CD's. You can use any USENET sesarch engine you want, but I suggest you use http://binsearch.info which is simple and effective. So go there, and look for Deep Purple: