Scotland’s biggest music festival will see 85,000 people descend on Balado, Kinross-shire, for the three-day event.
Franz Ferdinand, James Morrison and Maximo Park were among those who played on Friday, with Kings of Leon headlining.
Saturday’s line-up includes Razorlight, Paolo Nutini and Lady Gaga, with The Killers headlining on the main stage.
Glasvegas and The Manic Street Preachers will also perform.
Forecasters said that revellers can expect fine sunny weather on Saturday, with temperatures in the low 20s.
Rain will move in during the early hours of Sunday morning but will clear during the day, with sunny spells and a few showers later on.
There is a greater police presence on-site this year, following last year’s stabbing, and officers have been patrolling the campsite since Thursday night when people were first allowed in.
Drug amnesty bins will be placed at the entrance to the campsites, where people can dispose of any illegal substances without being excluded from the event or prosecuted. Plainclothes officers and sniffer dogs will be at the festival.
So far there have been 18 arrests, all for minor offences, with reports of 43 thefts, two petty assaults and 20 drugs offences.