This is a long way from sittin' on a bar stool with a mike and a tip jar," says Kenny Chesney, a day before firing up almost 50,000 fans June 24 at Qwest Field stadium in Seattle. Pre-show jitters? Not so much. "Every night on the road is summer vacation," says the singer, who gave PEOPLE a peek at backstage life during his 54-city tour. Intent on keeping the mood light, he eagerly led the party patrol by swigging sugar-free Red Bull and rum, slaying his band and crew with an air-guitar-accompanied rendition of Van Halen's "Jump" and carting around a stuffed 235-lb. marlin in a sombrero just because "it makes people laugh." Says opening act Dierks Bentley: "Touring with Kenny is like being in high school—we don't want to graduate because it's too much fun."