I'm thinking of recording a mixtape using only beats from Dilla's beat tapes. Problem is a lot of them are low quality recording. Can I do anything to even slightly improve this? Also, there's a lot of hissing on some of them. Can I get rid of this? I don't have any music editing software really except virtual Dj which I just use to loop a few bars when writing to a song. Can I do anything with that? I know Audacity is free, would that be of use?