Trombone Shorty at Virgin Free Fest (09/15/10) Photo: Jon Klemm Andrews and his bandmates, Orleans Avenue, spent nearly an hour effortlessly leap-frogging among nimble jazz, classic New Orleans brass, viscous funk, silky soul — they even puffed their chests out for a take on Lil Wayne’s “Lollipop.” But audience members didn’t move their leaden feet…