Emily Sater's friends aren't allowed to see her dad's musical. Never mind that Spring Awakening is based on a century-old play about adolescence. Forget that it swept the 2007 Tony Awards, just began a national tour, and that many of her friends already own the soundtrack. The parents won't budge. Maybe it's the fatally botched abortion that gives them pause. Or the masturbation. Or the copious sex, both gay and straight. Or the suicides.

"Some people have messed-up childhoods and then write plays about it," playwright Steven Sater cackled over the phone from his home in Los Angeles. "I went the other way around—I wrote a musical to mess up my kids!"

Not likely. In Spring Awakening—as in life—it's the silence, not the disclosure that causes the damage. The original play, written in 1891 by Frank Wedekind, is a condemnation of priggish and cruel adults who won't discuss sex with their children. The result, of course, isn't abstinence: It's all of the tragedy—and a little of the comedy—of young people learning about sex by trial and error. (Paying attention, Governor Palin?)

Sater met musician Duncan Sheik on January 2, 1999, and they wrote a song together that very day. Sater gave Sheik a copy of the 1891 Spring Awakening and suggested they work on an adaptation. "Everyone was thinking millennial thoughts at the time," Sater says. "And I thought, what a beautiful way to look forward by looking back." The result is a rock musical in sepia tones—schoolboys in black, 19th-century uniforms singing into microphones about stirrings in their loins, a piano teacher's breasts, and existential despair: "It's the bitch of living/And living in your head/It's the bitch of living/And sensing God is dead."

Against all expectations, Spring Awakening was a massive hit. "When we moved it from off Broadway to Broadway, our own producers called it a suicide mission," Sater says. The reviews were excellent, the audience surged, and next year it will open on three other continents.

"Our commercial success has opened the door and emboldened people to produce and write more adventurous musicals," Sater says, including Passing Strange (a picaresque about a young black musician who leaves South Central Los Angeles for Amsterdam and Berlin) and Bloody, Bloody Andrew Jackson (an excellent emo-rock musical about the seventh president that premiered in Los Angeles in January).

"And," Sater adds, "it gives the lie to the idea that kids aren't serious-minded, that all they love are video games, and that they can't be moved by a piece of literature."

Spring Awakening runs Oct 14–19 at the Paramount Theatre.