one of the biggest pop stars in the world, Rihanna, and the best-selling UK band Mumford and Sons are to headline the 20th T in the Park festival.

First staged in Strathclyde Park in 1994 with a line-up featuring Primal Scream and Oasis, the successful annual music festival will be billed as T20 next year and also feature Paloma Faith, alt-J, Jake Bugg and Of Monsters and Men, its organisers said last night.

T in the Park tickets for 2013 will go on sale this Friday from 9am.

Rihanna has sold more than 180 million records and is the top-selling digital artist of all time. Mumford and Sons had a number one album with Babel, which became the fastest-selling album of the year in the UK and US. They will headline T in the Park for the first time.

Alt-J won the prestigious Mercury Music Prize this year.

Geoff Ellis, the director of the festival, said: "It seems like only yesterday that the first band took to the stage at Strathclyde Park for our inaugural T in the Park in 94, now here we are in 2012 announcing two of the of the world's biggest and best acts to headline our 20th year.

"We have always been incredibly proud of the line-up that we are able to bring to our T in the Park fans and this year is no exception."

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