I have an older iPhone4s which has a TON of music i had from my old mp3 days. I decided to enable iTunes match on my account (using my desktop computer which has no music). I now want to activate iTunes match on the iPhone 4s, but it gives me a warning that my music will be replaced on the iPhone 4s if I activate. Question is.. is this true? Will all my old mp3s be now replaced with my empty itunes match list from my desktop ? I actually want to reverse actually, for all my old mp3s to be synced into my iTunes match account so I can use it on my other devices Thanks !