ROOS IN THE TOP PADDOCK Australia’s Circus Oz returns to Cal Performances Friday, Saturday and Sunday for what’s described as “their renowned brand of collective mayhem.” “Stunt-jumping acrobats contest physics, fearless aerial artists laugh at gravity, slapstick knockabouts descend into chaos, and live onstage musicians rock the house.” The matinee performance on Saturday has special Family Fare series pricing. At Zellerbach Hall on Friday at 8 p.m., Saturday at 2 p.m. and Sunday at 3 p.m. Tickets available from Cal Performances.