I dunno if they redid any of the sounds/music, it all sounds the same as the original to me.
only thing they fucked up is the ocarina controls. by that I mean is that if you're used to the diamond pattern of the c buttons for the ocarina, then the buttons aren't in the same layout for the songs.
For instance, zelda's lullaby is < ^ > < ^ >, but on 3ds it's ^ > <, ^ > <. So that's kinda dumb.