SNL 1977 - Lorne Michaels "raised his middle finger at [Elvis] Costello and kept it up until the unapproved song was over."
From wikipedia: Costello wanted to play "Radio Radio" on SNL. Columbia Records, however, was interested in having an already-established song performed on SNL, to increase interest in the band before the American release of My Aim Is True and This Year's Model. In the event, Costello began the SNL performance by playing "Less than Zero." However, after a few bars, he turned to the Attractions, waving his hand and yelling "Stop! Stop!," then said to the audience, "I'm sorry, ladies and gentlemen, there's no reason to do this song here," possibly referring to the fact "Less than Zero" was written as a reply to British fascist politician Oswald Mosley. However, SNL music director Howard Shore attributes the move to Costello's bucking pressure by his music company to play "Less than Zero" on the show.[1] He then led the band in a performance of "Radio Radio."
Go HERE to see the actual performance
I was home for xmas from the University of Florida and up late watching SNL with my parents. I laughed when I saw it because I though Costello was a spazz and making fun of punk music, which I didn't think was very musical. Little did I know I was watching history.