From "Infamous moments in Saturday Night Live history":

On December 17, 1977, Elvis Costello and the Attractions performed as a last-minute replacement for the Sex Pistols, who were unable to obtain passports. NBC and the show's producer Lorne Michaels didn't want the band to perform "Radio Radio", since the song protests the state of the media. The band defied them by beginning to play their song "Less Than Zero", stopping, with Costello telling the audience that there was no reason to do that song, and telling the band to play "Radio Radio" instead. It infuriated Michaels because it put the show off schedule, and the band were barred from performing again. ...Eventually Lorne Michaels put his grievances aside, lifting the ban, and ...Costello would appear as musical guest in 1989 and 1991. He also reprised his performance of "Radio Radio" with the Beastie Boys for a 25th anniversary special aired on September 26, 1999.