With regards to 'covers' Joolsburger, you've already exempted jazz for some reason...? Then what about classical music? - by and large for the last 1000 years this has been musicians/singers performing music which somebody else has written. Does that make classical worthless, or 'theft'? I should hope not...a 'cover' (an unfortunate term in my opinion) is merely an interpretation of music which somebody else has written. Unfortunately most modern covers are performed by mediocre pop acts, which gives covers in general (rather than just the crap groups in question) a bad name I understand where you're coming from, but your sweeping generalisation is particularly unfair to a lot of great and very talented musicians.