Gates open for Radio 1's Big Weekend in Londonderry
Thousands of music fans are at Radio 1's Big Weekend, which kicked off in Londonderry at 3pm.
Calvin Harris is the first headliner for the three-day event in Derry's Ebrington Square.
Tonight's line-up will focus on dance music and 1Xtra, with acts like Rita Ora and Maverick Sabre with Dizzee Rascal opening the main stage.
Problems at Heathrow disrupted travel plans with AlunaGeorge, Rudimental and Angel Haze all pulling out.
Radio 1 controller Ben Cooper has said the event will go on as scheduled, despite flight delays for artists such as Rita Ora and Wiley.
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.
Other acts performing across the weekend include Olly Murs, The Vaccines and Foals.
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."
Hannah Davidson and James Woods (pictured above), both 18, were the first people through the gates at Big Weekend.
James said: "I feel absolutely amazing, we are the first people here."
Hannah added: "We've been waiting since 11 this morning. The buzz in the city is amazing. I can't wait to see Calvin Harris and Chase and Status."
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 is 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."
Shannon, 16 and Julie, 17, (pictured above) have bagged a pair of tickets to Big Weekend.
Shannon said: "We were hoping it would come here. It's really nice because it's in between my exams. I did two exams yesterday, so I was looking forward to it.
"It's really good to give Derry a boost and have something that brings everyone together."
Others to perform on Sunday include The Script and Macklemore & Ryan Lewis, whose single Thrift Shop is the best-selling of 2013 so far.
There's more information on BBC Radio 1's Big Weekend Derry-Londonderry website.
Follow @BBCNewsbeat on Twitter