One Direction have opened BBC Radio 1's Big Weekend, with thousands of screaming fans welcoming them to the stage.
The boyband kick-started the party at Glasgow Green, where up to 50,000 revellers will attend the festival over two days.
They opened the main stage by performing many of their hits, including What Makes You Beautiful, Midnight Memories, Little Things, finishing with Best Song Ever.
Other acts performing on the main stage today are Calvin Harris, Pharrell, Bastille, Jake Bugg, Lily Allen and Ed Sheeran - with Coldplay headlining.
Example, Lorde, Twin Atlantic and Bombay Bicycle Club are taking to the In New Music We Trust stage.
A warm-up event took place last night as 14,000 dance music fans got the celebrations under way in the city's George Square.
Pete Tong, Tiesto, Danny Howard and Martin Garrix took to the stage as well as other Radio 1 DJs Annie Mac and Zane Lowe.
Kings of Leon, The Vamps, John Newman, Rita Ora, The 1975, Tinie Tempah and Paolo Nutini will all perform on the Sunday, with Katy Perry closing the festival.