Typically, Al makes his own demo of a song, which may be in varied states of completeness. The band then does a demo with direction from Al regarding how closely to follow (or not follow) his demo. The band demo is usually very close to the final version (or I should say the final is a polished version of the band demo.)
The only song that attempted but ultimately came out completely different, was Buckingham Blues, which started as a John Cougar parody: The Ballad of Chuck & Diane. There was a straight ahead parody version demo'd by Al and me, then another that was more of a style parody but still obviously close to the original, featuring Jim and Steve (January, 1983.) But the song did a 180 and became a blues thing instead.
Although this process normally applies to originals
only, a few early parodies were demo'd - I love Rocky Road, Ricky, and Ballad of Chuck & Diane (which got nixed and then
evolved.)

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