Good luck on this. Most music sold is edited and compressed, especially if on cassette or vinyl, to work within the available S/N of tape and disc. Dolby and dbx are forms of "companding." Rock/pop tends to be highly processed.

Short of original studio recording tracks at 96k kHz/24-bit, or original studio tapes, it is going to be tough to find anything "un-molested."

Reread the above thread for the suggestions as to ways to get good video recordings by today's generally accepted standards at affordable prices.