High School Musical 3 SING-ALONG By on November 3, 2008 High School Musical 3: Senior Year will follow in the footsteps of Hairspray and Mamma Mia! on Friday, by offering a sing-along version with onscreen lyrics in 125 theaters, reports E! Online. HSM3 has been the No. 1 movie the last two weekends, grossing $61.8 million through Sunday. Would you go to the sing-along? No related posts.