The Scissor Sisters' third album, Night Work, is due out on 28 June
Scissor Sisters, Tony Bennett and Ozzy Osbourne will perform on the first three nights of July's iTunes Festival in London, organisers have announced.
The free event, billed as "31 nights, 62 bands, one venue", takes place at Camden's Roundhouse. Further acts will be announced in the coming weeks.
Fans can apply for free tickets on the festival's website and Facebook page.
Oasis, Franz Ferdinand, Snow Patrol and Bloc Party were among acts performing at last year's festival.
Babydaddy, of Scissor Sisters, who will headline the festival's first night on 1 July, told London's Metro newspaper: "We can't wait to tickle your fancies with songs new and old."
Osbourne, 61, told the paper his planned appearance had "all the makings of a great gig".
"I've never performed at the Roundhouse. It'll be fantastic to do an intimate show there for the fans."
Recordings of all performances will be made available on the iTunes website, while concerts will be broadcast on ITV2 and radio station XFM.