I’m not enraptured by the new musical “Next to Normal,” but I can’t help but admire its soaring ambition and the craft that brings it very close to reaching its aim. Alice Ripley brilliantly slashes through the central role of Diana, a suburban mother who is coping, or more often failing to cope, with debilitating mental illness.

Tom Kitt has packed his score with lots of jagged energy and emotion, to the point that the cast spend much time belting at the high end of their range. It’s viscerally exciting, yes, but this full-roar approach doesn’t quite match the breadth, variety and complexity of bookwriter Brian Yorkey’s intelligent and involving story. That said, the song “I’m Alive” was running through my head for much of the following day, and that’s a very good sign.

The show is definitely Ripley’s, and I’d be surprised if she doesn’t get a Tony nod for this brave performance. Also quite good is Aaron Tveit as her strangely affectionate son Gabe: the vocal gymnastics he performs with his clear, high tenor are dazzling. He’s also quite easy on the eyes and the audience on the night I went was packed with young Tveit fans of both sexes.

This didn’t move me the way that “Spring Awakening” or “Rent” did, but it’s the only truly original musical on Broadway this season, with a raw honesty than none of the other musicals this season could hope to touch. That alone deserves praise.

Tickets: www.telecharge.com