For six seasons, the hit musical comedy Glee featured covers of all different kinds of classic songs. During its run, the show’s cast put their spin on such legendary tracks as “Sgt. Pepper’s Lonely Hearts Club Band” by The Beatles and AC/DC’s “Highway to Hell.” But as popular as the series was, not every artist was eager to have their music associated with it. And what’s more, a couple of them were very open about their reasons for rejecting offers from Glee.

In 2011, Guns N’ Roses guitarist Slash was asked how he’d feel if Glee covered one of his old songs, and he revealed that he’d actually already put the kibosh on that happening. “In the current climate of what’s going on in entertainment these days, I try to be more optimistic than negative because it’s really easy to get negative about it, but I draw the line at Glee,” Slash told Entertainment Weekly.

He went on to say, “Glee is worse than Grease and Grease is bad enough.” Glee creator Ryan Murphy responded to Slash’s jabs in an interview with The Hollywood Reporter, saying, “Usually, I find that people who make those comments, their careers are over; they’re uneducated and quite stupid.”

Dave Grohl and Slash Really Didn’t Want Their Songs on ‘Glee’

If Murphy’s to be believed, then we can count Foo Fighters frontman Dave Grohl as yet another washed-up fool. Later that same year, Grohl spoke up in defense of Slash and said that it was “every band’s right” to turn down the show. Additionally, Grohl expressed his frustration with Murphy’s offense that some people weren’t begging to work with him. As Grohl put it, “F—k that guy for thinking anybody and everybody should want to do Glee.”

Grohl’s words seem to have made Murphy change his tune a bit, as he was less hostile when the subject came up again the following month. At that point, Murphy admitted that he completely understood why artists didn’t want other people to interpret their work and that he respected their decision. In conclusion, Murphy said, “The Foo Fighters are brilliant. We’d love to do one of their songs, if they were ever interested. But if it’s not their thing, then OK.”