Charli XCX performed her 2014 hit Boom Clap with guest Chappell Roan at the Kia Forum in Los Angeles on SaturdayCultureOct 18 at 11:00 AM – Oct 18 at 7:16 PM3 outletsUnited StatesRolling StoneSee Charli XCX and Chappell Roan Perform 'Boom Clap' in Los Angeles Oct 18 at 11:00 AMThe Orange County RegisterCharli XCX delivers surprise Chappell Roan duet and new songs at Kia Forum Oct 18 at 12:08 PMVarietyCharli xcx Brings Out Chappell Roan for ‘Boom Clap’ at Los Angeles Concert Oct 18 at 1:53 PM