Belfast Biggest Weekend gets under way at Titanic
Ash, Manic Street Preachers and Orbital are among the acts performing at the BBC's Biggest Weekend in Belfast.
The concerts at the Titanic Slipways take place on Friday and Saturday.
The first acts are due on stage each day around 13:00 BST with the last acts closing at about 22:30 BST.
Crowds of up to 18,000 are expected for both concerts, although there are some tickets still available at the on-site box office.
The Belfast event is one of four taking place across the UK, with the others in Perth, Swansea and Coventry.
On Friday, Orbital, Beck and Manic Street Preachers are the headline acts on the main stage, while local DJ and producer David Holmes plays the 6 Music Recommends stage.
On Saturday, Underworld, Franz Ferdinand and First Aid Kit top the bill, along with Ash.
Live coverage will be broadcast on BBC 6 Music, while the Gerry Kelly show on BBC Radio Ulster will also broadcast from the event on Friday and Saturday.
BBC 4 will provide TV coverage of the Belfast concerts on Friday and Saturday night.
The weather for both days is also expected to be hot and sunny, so concert goers have been advised to remember to wear appropriate clothing and bring sun screen.