Co-starring in “High School Musical,” Lizzie Weiss nightly engages in a bit of self-hypnosis. Just before the curtain rises, she tries to forget everything she learned after high school.

That must take work. The 22-year-old actress has gone far in the competitive world of musical theater ever since she graduated from Beverly Hills High.

Much of that success has come in the first national touring company of “High School Musical,” which begins a 12-day run at San Francisco’s Orpheum Theatre on Tuesday, April 15.

Premiering as a 2006 Disney Channel movie, “High School Musical” tells an updated Romeo and Juliet tale of two star-crossed juniors auditioning for the school musical. The story takes a lighthearted look at the strict social order of high school life, including dancing jocks, singing nerds and just enough G-rated romance to charm the Hannah Montana set.

A ratings powerhouse, “High School Musical” soon spun off into a cable TV sequel, a multi-platinum-selling soundtrack CD and now an upcoming motion picture.

The live stage version premiered in Atlanta last year, with Weiss in the original cast. She plays Martha Cox, a so-called brainiac with a secret love for rap music. Weiss has a few solos as well as a show-stopping moment when she gets to strut her stuff as a hip-hop dancer.

Not bad for a former Camp Ramah regular and one-time High Holy Days substitute for the cantor at her Beverly Hills congregation, Temple Emanuel.

Weiss says the cantor’s compliments on her singing first made her believe she had a shot at a show business career. But it didn’t start there. Growing up one of three triplets, Weiss found herself in friendly competition with her brother and sister, both of whom also brandished musical talent.

“There was always singing in the house,” Weiss remembers. “We grew up on people like Lionel Richie and Nat King Cole. But we were definitely not kids listening to Broadway CDs at age 6.”

Synagogue life was important to the family. Weiss sang in her temple’s children’s choir, and even served as a soloist during the High Holy Days one year. Weiss also attended Jewish summer camps for most of her youth, and she counts two rabbis in the family.

As a teen, Weiss became a star in Beverly Hills High’s fabled drama department, landing roles in show after show. She went on to attend U.C. Irvine, completing her theater degree in less than three years.

From there she went straight to New York, hoping to break onto Broadway. It wasn’t long before she auditioned for the role of Martha in the premiere production of “High School Musical” in Atlanta.

“The character in the movie had only one line,” notes Weiss of Martha, whose role was significantly beefed up for the theatrical version. “I’m in the entire show and have several solos.”

Aside from the spotlight time, Weiss hopes to inspire girls who may not fit the Vogue magazine body type. “[Martha] gives kids another type of role model, a bigger girl who can sing and do hip-hop dancing,” says the plus-sized Weiss.

The touring production is set to wrap up in August, back in Atlanta where it all started. This being a Disney project, of course a sequel is in the works, and Weiss hopes she will return on stage as Martha in “High School Musical 2.”

Even if she doesn’t, Weiss appears to have found that lucky break so many Broadway hopefuls never get. “I have been working for 16 months straight,” she says. “I’m very blessed not to be a waitress starving right now.”

“High School Musical” plays Tuesdays through Sundays, with Wednesday and weekend matinees, April 15-27 at the Orpheum Theatre, 1192 Market St., S.F. Tickets: $23-$85. Information: (415) 551-2020, or online at www.shnsf.com.