Whoa there yourself. First, I never said it was "the same,"
I said it was different and you disputed that. If you disagree with "different" I'm not exactly sure what other possibility you think there is since "not different" implies "the same".
You're the one who made the original claim that downloading a copy of something you own would fall under fair use and is therefore legal, so the burden of proof is on you. What part of copyright law would give people the right to download music that they've purchased in another format?