Legally Blonde, the third in the Prizery's Summer Theatre season, opened Thursday night. “Legally Blonde” is the high-energy, contemporary pop-rock musical tale of Elle Woods, a perky UCLA sorority president who gets engaged to Warner Huntington III. But when he dumps her, seeking someone more “serious,” Elle follows him to Harvard, where she gets admitted with the backing of a cheerleading squad. Once on the Cambridge campus, Elle gets snubbed for her wardrobe and her platinum blonde locks. As Elle gets more serious about herself and her law degree, though, hilarity ensues. The film version starred Reese Witherspoon. The Broadway musical was nominated for seven Tony Awards in 2007, after its Broadway premiere. Some of the show’s material should be considered PG-13. “Legally Blonde” opened Thursday for 12 shows. For tickets: (434) 572-8339 or http://www.prizery.com.