Phoenix, De La Soul, St. Vincent, The Chainsmokers, Sturgill Simpson, and Over 30 Acts Announced for Grandoozy 2018 The inaugural Grandoozy lineup has just been released with a group of noteworthy headliners including Kendrick Lamar, Florence + the Machine, and Stevie Wonder. Event organizers from Bonnaroo and Outside Lands Music Festival have teamed together to bring a multiple stage, multiple day music festival to the Denver area on September 14-16. Overland Park is just south of Denver, and showcases the Rocky Mountains in the background. Additional acts for Grandoozy 2018 include: Logic, Miguel, Young the Giant, The War On Drugs,