The drummer with US rock group Foo Fighters, Taylor Hawkins, has died aged 50, the band have announced.
The band said they were "devastated by the tragic and untimely loss" in a statement on social media.
Hawkins played with Foo Fighters for more than two decades, joining shortly after they finished making their 1997 album The Colour and the Shape.
The band are currently on tour in South America.
"His musical spirit and infectious laughter will live with us forever," Foo Fighters wrote.
"Our hearts go out to his wife, children, and family, and we ask that their privacy be treated with the utmost respect in this unimaginably difficult time."
Musicians paying tribute included Ozzy Osbourne who said Hawkins was "truly a great person and an amazing musician".
Miley Cyrus, who was part of the festival line-up, said she would dedicate her Saturday show to Hawkins.
Former Beatles drummer Ringo Starr also expressed his condolences. "God bless Taylor," he wrote.
"Peace and love to all his family and the band peace and love."
Kiss member Gene Simmons said he was "shocked and saddened" by the news of Hawkins' death.
No cause of death has been given.