I just thought of another one. Aerosmith used to cover Fleetwood Mac's Rattlesnake Shake early on in their career (there's a 1971 recording on Pandora's Box), and their version was 10 minutes long and incorporated a lot of original music, including one riff that was later used as the outro for Rats In The Cellar in 1976. That alone is cool, but what really pushed this over the edge for me was when I was listening to demos of the Rocks sessions that someone had posted on YouTube (and unfortunately, they're no longer available), and on the demo for RITC, the outro is slightly longer, and it features another part of the Rattlesnake Shake ending that got cut from the final version of Rats In The Cellar. Aerosmith still play Rattlesnake Shake every now and then, and when they do, they usually pair it up with Rats In The Cellar.