In the 50-year history of Saturday Night Live, the show’s myriad musical highlights have been paired with plenty of controversies, but creator and producer Lorne Michaels has asserted that no musical guest has ever been barred from returning.

Michaels’ claims emerged in the new three-hour documentary Ladies & Gentleman… 50 Years of SNL Music, which premiered on NBC on Monday (Jan. 27). Alongside notable revelations in regards to the show’s musical history (including the fact that no one seems to know the melody to the SNL theme song), Michaels pushed back at long-standing reports that numerous artists have been banned from the show for various reasons.

“I’ll read it sometimes in the Post, ‘So and so’s banned for life,’” Michaels explained. “We’ve never banned anyone. We’re way too crass and opportunistic. If something’s hot, we’re going to go for it and have it on.”

Though it’s not exactly clear where the reports that artists have been banned from SNL have emerged from over the years, a number of controversial appearances make it easy to see why bans would be expected.

One of the earliest incidents of an apparently banned performer came from a December 1977 episode in which Elvis Costello stepped in for the Sex Pistols. Despite planning to perform “Less Than Zero”, Costello switched up his set at the last moment and instead performed “Radio Radio” – a track that was critical of commercial radio in his native U.K. Undeterred by the negative reaction his appearance generated from the show’s staff, Costello later returned to the show in 1989, 1991, and again in 1999 where he parodied his first performance alongside the Beastie Boys.

Among the most notable examples of controversial musical guests was that of Sinéad O’Connor, who tore up an image of Pope John Paul II during an a cappella performance of Bob Marley’s “War” in 1992. Protesting sexual abuse within the Roman Catholic Church, O’Connor’s urging for viewers to “fight the real enemy” became one of the most infamous moments on the show’s history.

Other instances also include Los Angeles punk outfit Fear appearing on the show at the insistence of John Belushi in 1981, with their rowdy set reportedly causing $500,000 in damage. A 2004 performance from Ashlee Simpson also gained international notoriety after she was revealed to be lip-syncing due to illness, though she would later return the following year without incident.

The nascent documentary also featured further information about Rage Against the Machine’s 1996 performance, in which they appeared alongside then-presidential candidate Steve Forbes. 

Following a version of “Bulls on Parade” (which was planned to feature upside-down American flags hung from their amps until stagehands intervened), bassist Tim Commerford vented his frustration by throwing one of the flags into Forbes’ empty dressing room. The incident caused the Secret Service to respond on behalf of the billionaire, locking the band down in their dressing room until the completion of the show.

The 50 Years of SNL Music documentary – which is co-directed by Oscar-winning Roots drummer Questlove – is part of SNL’s 50th anniversary programming, and arrived following the premiere of SNL50: Beyond Saturday Night on Jan. 16.