There's nothing Pollyannaish about the musical Next to Normal. It's the story of a housewife and her family, all of them struggling with her bipolar disorder and each of their individual frustrations: sex, academics, control, fear of the future, nostalgia for the past, and crippling grief. The new musical by Brian Yorkey and Tom Kitt (new to Seattle, anyway—it made its off-Broadway premiere in 2008) is dark and sometimes nearly aggressive in its book and lyrics. As David Armstrong, the 5th Avenue's artistic director, notes in the program, Next to Normal joins a long line of musicals—from Show Boat to Sweeney Todd—that were initially considered too dismal to be popular, but then succeeded with audiences and critics.

And Next to Normal is no joyride. "That's fucked," the characters keep saying to each other, as a way to end conversations, while the mother (Diana, played by Alice Ripley) spins in and out of control, trying—and often failing—to cope with her mania, depression, and delusions. In one of the show's gentler, sweeter songs, the daughter's love interest sings about the imminent destruction of the planet and how "I may be lazy, a loner, a bit of a stoner, but I could be perfect for you." Then there's the sardonic, wry Diana, who, like many bipolar folks, vacillates between trying to deal with her problem and resenting anyone who suggests she even has a problem. When one of her doctors asks her about happiness, she fires back: "Most people who think they're happy haven't thought about it enough—most people who think they're happy are just stupid." Then she leans back in her chair with a diabolical, two-faced smirk: Half of her wants to seduce her doctor, and the other half wants to eat him alive.

As Diana falls in and out of "normal," her family follows: son Gabe (Curt Hansen, playing a mercurial and seductive character who is half Oedipus and half Thanatos), daughter Natalie (Emma Hunton, long-suffering and overachieving), and husband Dan (the family's weary anchor, normally played by Asa Somers, but given a charming and strong performance by standby Jason Watson the night I saw the show).

The score, despite some electric guitars and a few rock 'n' roll moments, isn't a radical departure from what you've heard from Broadway before. Nevertheless, Next to Normal has had to build a special shelf—perhaps next to its medicine cabinet—for all of its awards: the 2010 Pulitzer, a fistful of Tonys, some Drama Desk awards, some audience awards. At the performance I attended, more than one person volunteered to me that they'd seen Next to Normal on Broadway and that they were coming to see it here because the original had made them weep.

Though Brian Yorkey's book is original—not based on a movie (Shrek, Young Frankenstein) or an exhumed old text (Spring Awakening)—Next to Normal as a whole doesn't substantially bust out of the form of The American Musical. It is a good, sturdy, slightly more contemporary version of The Musical as you know it. For those of you who like The Musical, that's a good thing. For those of you feel slightly bored by that proposition... well, you know.

The one strong drawback to this production is, unfortunately, the star's voice. Normally, US audiences would be delighted to see an original Broadway star in a touring production—but Ripley's voice seems tired and swallowed. She sings beneath her costars, in both pitch and volume, sometimes unable to hit her bottom notes. Back in 2009, Time Out New York described Ripley's voice as "steel wool: It's tough and cloudy at once, and it scrubs to the core." It seems that her steel wool has scrubbed for a few too many nights and worn itself away. (Her vocal troubles have already been noted on blogs from Connecticut to Seattle.) Ripley's performance as a sharp, haunted woman is still seductively dark. But she—and her producers—may want to give that throat a rest.