there's nothing wrong with it if you're not mass distributing it. for example, I love the guitar riff for Moby Dick, but I don't necessarily want to listen to the drum solo every time. so I took out the drum solo and put Livin Lovin Maid the middle of the song. whenever my friends hear it they ask where I got "that version" so I send it to them. of course all of my friends I give it to have Led Zeppelin II.