Billie Joe Armstrong has had a "lot of fun" filming with Christina Aguilera on The Voice.
The Green Day frontman has signed on to be a guest mentor to Christina's chosen acts on the TV talent show and enjoyed his first days on set filming.
He said: "The Voice is not moulding artists, it's just giving them a little bit of guidance and direction without giving them a complete makeover."
Aguilera announced his arrival on Twitter, writing: "Welcome Billie Joe (@BJAofficial) to #TeamXtina! We are ready to rock out in Season 3 (sic)."
Taping on The Voice - which also sees Adam Levine, Cee Lo Green and Blake Shelton coach teams - began in June and the show is set to begin in the US in September.
Armstrong is known for his humour and will likely add a little of his punk rock personality and maverick spirit to his mentorship.
The rocker recently explained his band's decision to release three albums, ¡Uno!, ¡Dos! and ¡Tre! in the space of a few months is something of a risk.
He said: "This could possibly be the greatest idea we've ever had or it could possibly be the dumbest idea we've ever had. And that's really exciting to think about.
"We don't have a f***ing clue what we're doing as far as the future is concerned. And it's kind of exciting to think of it that way."