Music fans get ready for Radio 1's Big Weekend 2013

Thousands of music fans are preparing for Radio 1's Big Weekend which kicks off in Londonderry later.

Calvin Harris is the first headliner for the three-day event in Derry's Ebrington Square.

Friday's line-up will focus on dance music and BBC Radio 1Xtra with acts like Rita Ora and Rudimental with Dizzee Rascal opening the main stage.

Tickets for the festival have already been allocated. Gates to the event open at around 3pm (15:00 BST).

Gates will open at around midday on both Saturday and Sunday, 25 and 26 May.

The event finishes around midnight on Friday and around 11.30pm on Saturday and Sunday.

Biffy Clyro headline the Main Stage on Saturday night, with Bruno Mars closing the show on Sunday night.

Calvin Harris, Biffy Clyro and Bruno Mars will perform in the city of Londonderry

Other acts performing across the weekend include Olly Murs, The Vaccines and Foals.

Main Stage

Wretch 32 is performing on the Main Stage on Sunday.

He said: "Big Weekend is the first festival I ever went to in my life when it was held in Swindon so to be asked to come back on the bill, I'm absolutely ecstatic."

Mercury Music Prize winners Alt-J are also performing. Drummer Thom Green said: "I can't wait. We love Radio 1 and to be involved in the festival is great."

Jake Bugg's on the main stage on Sunday and said: "In Derry, they're not spoilt for music so I think the crowd will be quite appreciative."

He also said he'd change his set according to the mood of the crowd.

"If everyone's talking there's no point playing a soft song, give them a tune they can dance to."

Others to perform on Sunday include The Script and Macklemore & Ryan Lewis, whose single Thrift Shop is the best-selling of 2013 so far.

Dizzee Rascal, Hayley Williams' Paramore and Olly Murs will also perform

Despite tickets being allocated, their release was delayed for 24 hours in April because of technical issues.

Radio 1 has also said it will work to stop the secondary sale of any tickets.

Jason Carter, the BBC's head of live music and events, popular music, said: "The last Big Weekend in the city in 2004 was a legendary music moment in Northern Ireland and it's so great to be able to return with an even bigger show second time around."

There's more information on BBC Radio 1's Big Weekend Derry-Londonderry website.

Follow @BBCNewsbeat on Twitter