Even before Andrew Lloyd Webber decided to portray Jesus Christ as a psychedelic savior, the integration of musical theater and rock and roll was a perpetual, but generally elusive, goal of upstart composers. The main hurdle confronting such an undertaking has remained essentially the same since the sixties: The stage (at least that kind of stage) is about the last place you’d expect to find anything authentically gritty or “street,” making it tough to pull off believable theater-as-rock. The cast albums to such endeavors tend to be even less successful. Rent’s cast recording, for instance, fills two CDs, incorporating plenty of dialogue and incidental music to drag listeners through every twist and turn in the plot. No self-respecting rocker would commit such tedium to disc. Which is not to say that rock and theater exist in utterly parallel, noncontiguous universes – it’s just a tricky balance to strike. The Who’s Tommy (1969) worked; The Who’s Tommy (1993) didn’t.

The latest entry into this uneasy dialogue between pop-culture forms was Hedwig and the Angry Inch. Stephen Trask and John Cameron Mitchell, the pair who created the show last year, had a secret weapon that put them leagues ahead of the competition: glam. They knew that the only kind of rock that would lend itself to successful simulation in the theater was that which makes no claim to authenticity at all, instead celebrating, even flaunting, its artifice, its campiness – its very theatricality. No form of rock has ever reveled quite so self-consciously in its own stagy, rhinestone-encrusted fabulousness as the glam-rock concocted by David Bowie, T. Rex, and Roxy Music in the early seventies. (It didn’t hurt that Trask was an actual fixture on the New York rock scene, having fronted a band, Cheater, at clubs like Don Hill’s for years before he wrote the music for Hedwig.)

Glam – which mixes a little Beatles bounce here, some music-hall kitsch there, and a sprinkling of metallized sonic drama on top of everything – lends itself perfectly to Trask and Mitchell’s subject: a young East German, Hedwig, who undergoes a sex-change operation (a botched job that leaves her with the title’s “angry inch” between her legs) in order to marry an American soldier, move to a trailer park in the heartland, and pursue her dream of becoming a rock star. Hedwig – like the entire pop subgenre from which it borrows its ambitious sound – is about androgyny, life in a borderline state of being, and the inevitably disappointing pursuit of glamour.

The show is also part of a broader movement to revive glam that, sadly, has been about as successful as Hedwig’s sex-change operation. Though they’ve been hyped hard in the music press, genre-comeback vehicles such as Todd Haynes’s film Velvet Goldmine and Marilyn Manson’s Bowie-influenced album Mechanical Animals have been commercial disappointments.

Hedwig and the Angry Inch: The Original Cast Recording (Atlantic), released last week, succeeds as well as the show precisely because it doesn’t attempt to re-create the live performance. Instead, it stays true to the spirit of a musical whose only players are a four-piece band, the star, and a backup singer: Trask, Mitchell, and producer Brad Wood (best known for giving albums by Liz Phair and Ben Lee the perfect blend of dirt and polish) opted to make a real album – just twelve songs, with no filler dialogue – that can succeed or fail on its own terms. (This principle is taken so far that the record includes a song, “Random Number Generation,” that is not in the show itself.) We’re given, basically, a collection of pop tunes – cleverly written (by Trask), about as related to one another as those on a typical seventies concept album, and sung by an extremely expressive and funny interpreter (Mitchell).

Naturally, Mitchell is in character throughout the album, maintaining a convincing German accent and conveying Hedwig’s shifting moods of wistfulness, disappointment, and defiance. But the story line is alluded to more than it is depicted: Listening to the disc, you gather that Hedwig was born in East Berlin, but you don’t, for instance, learn the circumstances that have brought her to America. In the show, “The Origin of Love” is presented as a bedtime story told to the young, pre-op Hedwig; on the album, it’s simply a surprisingly touching rendition of the tongue-in-cheek creation myth from Plato’s Symposium. The twangy “Sugar Daddy” is like some hilariously heavy-handed take on Nina Simone: “Hansel needs some sugar in his bowl,” Mitchell coos over a bouncing backbeat.

The plot does crop up, but only occasionally, and often to less-than-subtle effect. The hard-charging “Angry Inch” contains the most expository material on the album: “I was left with a one-inch mound of flesh / where my penis used to be / where my vagina never was.” These details are rendered with discomfiting specificity – but how else are you to make sense of the title?

Hedwig’s liminality – she straddles, as the opening number notes, “East and West / slavery and freedom / man and woman” – is crucial to her success as a character. Similarly, the Hedwig album works because it falls between numerous categories: It’s neither a straight-up soundtrack nor a rock album, yet it’s both; it’s both self-consciously tacky camp and a sincere depiction of an outsider’s plight; it’s a bit of derivative, retro fluff and an energized romp through recent musical history. It’s both glitzy show tunes and gritty rock.