
4. Frank Zappa
Rock innovator Frank Zappa was invited to host SNL in 1978 after a musical performance two years earlier.
It was a disaster; Zappa went out of his way to be difficult, and lazily read from the cue cards to remind viewers that he wasn’t really trying. One of the writers, Don Novello, called Zappa “one of the worst ever.”
His unpopularity with cast and crew could have had something to do with their lax views on drug and alcohol consumption, while Zappa was strictly anti-drugs (surprising, considering how “out there” he could be). No matter the reason for his boorish behavior, he was given a lifetime ban from the show.

source: Death and Taxes
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