Of course, if a Broadway musical has any staying power at all, the cast album is cut and released before the show is crowned with the Tony Award. More and more, particularly when a show comes branded to Broadway with a familiar title, a familiar creative team, or big name stars, the album is out almost on the heels of opening night.

That's how it has been for the past two years, when I got a chance to review two cast albums before the Tony nominees, let alone the winners, were even announced. Otherwise, the cast albums of Once and Kinky Boots make for a fascinating study in contrasts - different kinds of music, different ways of constructing a musical, and different ways of presenting/annotating the CD.

Once: A New Musical (Sony Masterworks Broadway): My disappointment with this show was fairly well telegraphed by this cast album, which flees from the usual textures of Broadway musicals. The score by Glen Hansard and Marketa Irglová is folksy and zealously acoustic - a refreshing breakout for a while, but new frontiers on the 2012 Broadway songlist are more circumscribed and lugubrious than you'll find on the 2007 motion picture soundtrack. Gone are the uptempo "Fallen from the Sky" and its puckish Beatles flavor as well as three other songs, including the implausible deletion of the title number.

The best of the new works by Hansard filling the void is the enigmatic "Sleeping," which occurs just before the climactic "When Your Mind's Made Up," the song that rouses a record producer's enthusiasm during a studio session. But all Hansard's songs belong to Steve Kazee here, a vocalist who is more polished than the composer and hardly less emotionally powerful. Original cast co-star Cristin Milioti, smooth as she is, doesn't really replicate the ethereal heights we hear from Irglová or her sublime delicacy.

And after "Leave," a hair-raising vocal from Kazee that is the album's highlight, none of the songs really makes close contact with the story onstage. Laudably, the cast of Once refuses to do their cast album in a studio like everyone else, recording instead at a rehearsal hall. Unfortunately, when they reach the pivotal "When Your Mind's Made Up," none of the spontaneous combustion that occurs in every performance as the band's confidence grows is even attempted. So we miss the drama that routinely lights up this dreary show, even with the current leads who have none of the chemistry we find here between Kazee and Milioti.

This cast album might actually be rather pleasing to folkies who dislike Broadway musicals. But unless they replace the moribund leads now on Broadway - or they have superior protagonists on the tour headed to Charlotte - listeners who find this CD enticing might also be disappointed in the live show.

Kinky Boots (Sony Masterworks Broadway): Onstage and on record, here's how it should be done. "Charlie Price (Stark Sands) has suddenly inherited his father's shoe factory, which is on the verge of bankruptcy," begins the note by Kinky book writer Harvey Fierstein. Exactly how he should begin. Yet you'll find more in my above review about what happens in Once than you'll find in the entire booklet that accompanies the CD, and neither of its original creators could be bothered to participate. Instead there's a screed by director Enid Walsh, as self-absorbed as the rest of the project, describing how the Once cast coalesced into an ensemble, how they set up the recording, and extolling the lapidary miracle of a three-minute song.

Fierstein, on the other hand, coaxed lyricist/composer Cyndi Lauper out of her pop tune comfort zone, and the results are fairly astounding. Lauper's score not only integrates into a meaningful story, her songs usually push it forward dramatically. Nine of the 16 lyrics feature dialogue between two or more characters, beginning with "The Most Beautiful Thing in the World," a classically shaped opening number that involves everybody - Charlie and his father, Lola and his father, the shoe factory workers, and Charlie's material girlfriend.

Lauper works within herself, penning a song for Lauren, the honest working-girl who will supplant Nicola in Charlie's affections, that has an unmistakable Lauper stamp on it ("The History of Wrong Guys"). More often, she's torching the stage with songs that the guys can inhabit, particularly Lola, the flamboyant cross-dresser whose kinky design flair will be the salvation of the Price & Son shoe company.

There's a fair amount of spark from Sands singing Charlie's "Step One," but that is a mere foretaste of Tony Award winner Billy Porter's most commanding manifesto, "Sex Is in the Heel," with a small army of barn-burning backup vocalists. Nor is there any shortage of electricity - or kinkiness - in our first glimpse of Porter, "Land of Lola."

No doubt about it, this cast album will give you a vivid idea of what Kinky Boots is all about and whether you'll enjoy the live show. If you're like me, you will. As for my wife Sue, she wouldn't let me turn this CD off. Now that's awesome.