The Arctic Monkeys and Bjork are the first major acts to be confirmed for this year's Glastonbury music festival.
The Arctic Monkeys took the UK by storm in 2006
The Arctic Monkeys will headline the main Pyramid Stage during the event on Michael Eavis' Somerset farm in June.
"Most of the line-up's done now," Mr Eavis told BBC 6Music, adding that the "biggest band in the world" had also contacted him about performing.
But he denied it was U2 or Coldplay. "You won't know until after 1 April", when tickets go on sale, he said.
Fans will be able to pre-register for tickets during February by filling in a form online or from camping shop Millets.
They will also have to submit a photograph, which will be printed on their tickets in an attempt to beat touts.
Bjork is currently working on a new album
"That's called pre-registration exercise," Mr Eavis said. "From 1 April at 9am, the phone lines open for ticket sales.
"The first 150,000 people that come through that will be booked in. We'll already have the information on those people, their pre-registration forms and photos, so they can't sell those tickets on."
Co-organiser Emily Eavis told the BBC News website: "We're absolutely thrilled to be able to put Bjork and the Arctic Monkeys on because both are firm favourites in our household.
"The Arctic Monkeys have never done it so this will be their first year and Bjork has done the festival a few times now and is absolutely fantastic."
No date had been set to reveal the full line-up, but it would be "in the coming months", she added. But she refused to say which nights the Arctic Monkeys and Bjork will play.
Listen to the full Michael Eavis interview on BBC 6Music at 1300 GMT on Sunday.