I didn't see this when it was originally announced, but the Rodgers and Hammerstein Organization has made a complete recording of the score of Allegro, Rodgers and Hammerstein's third musical and by far their most ambitious. The recording will be released by Sony/BMG sometime later this year.
A synopsis of the show can be found here, but a synopsis can't do justice to how fascinating, if flawed, Allegro is. They'd completely revolutionized the musical theatre with Oklahoma! and Carousel, changing the definition of a musical from a loosely-constructed show based around performers to a carefully-assembled work of theatre where the writing and production were more important than any single performer. (And they proved that this was a sound business decision as well as an artistic decision: the reason Oklahoma! ran so long is that it could survive multiple cast changes, whereas most musicals were over as soon as the stars left.) With Allegro, their first original story, they tried to take this one step further and make a musical that was a 100% integrated theatrical experience: not just integrating the songs into the story, but having staging, sets, writing, acting and lighting all working toward the same overarching concept.
Oklahoma! and Carousel had been brilliantly directed by Rouben Mamoulian (film fans sometimes wonder what happened to his talent after the '30s; the answer is, he took it back to Broadway), but they still had relatively conventional sets and followed a conventional division into scenes. Allegro mostly did away with representational sets. In this it was influenced by Our Town and other set-less plays, but Allegro was actually more expensive to design and operate than other musicals, because in place of regular sets, there was an elaborate system of machines, sliding props, projections, and complicated lighting, all intended to make each scene flow into the next without breaks. The chorus sometimes sang, but more often talked to the audience and the characters like a Greek chorus.
And just as the scenes flowed one into the other, the score had fewer stand-alone songs than any musical in years; bits and pieces of song popped up here and there like leitmotifs (especially the opening number, "Joseph Taylor, Junior," repeated over and over at key points). Even when there were full-fledged numbers, they were assigned in unusual ways. The most beautiful ballad in the score, "(We Have Nothing to Remember) So Far," is given to a character who never appears in the show again after that one scene. (Stephen Sondheim, who was a production assistant on Allegro and has been trying to re-make it in one form or another for most of his career -- there's a party scene in Merrily We Roll Along that is almost a carbon copy of a similar scene in Allegro -- is the only other songwriter who really tried to revive this idea, and even he gave up on it eventually; since the late '70s he's gone back to giving all the big numbers to the big characters.) The choreography, too, mostly did without the big ballet set-pieces of the last two shows; there was lots of dancing, but in bits and pieces, with minor characters dancing to suggest what the major characters might be thinking. Agnes DeMille, who choreographed R&H's first two shows, became the first choreographer to be put in charge of directing an entire show; the task was too big for DeMille, who wasn't really cut out to be a director (she couldn't get away with treating everyone in the cast the way she treated some of her dancers), and Hammerstein wound up directing a lot of the scenes, but it was still the ancestor of the approach taken by Jerome Robbins or Bob Fosse, the idea that the direction and choreography needed to reflect the same approach.
Hammerstein's script has a reputation for being preachy and lecture-y. And it is that. But it is an interesting script for all that. The theme that "success" often means giving up something essential in ourselves was a timely one for the post-war era, and the second act is basically a long attack on for-profit medicine and the way it screws up what should be a doctor's priorities. The show is also, as Hammerstein himself said, autobiographical; I can't help thinking that the story of Joe, the man with noble ambitions, and Jenny, his bitchy wife who talks him into selling out, shows Hammerstein's worry about the partnership he'd formed with Rodgers. Hammerstein was Joe, the dreamy, impractical type who's always ambitious but not always successful (before he teamed with Rodgers, he'd had nothing but flops for ten years). Rodgers was practical, hard-headed and a little cold, like Jenny. Was Hammerstein worried about where Rodgers was taking him?
If so, maybe he was right to be worried. The relative failure of Allegro meant that they never did anything remotely that ambitious again. South Pacific and The King and I were big hits, but less experimental in writing or staging. All their shows after The King and I were essentially play-it-safe musical comedies. Some of those shows were better than Allegro; I don't think it's anywhere near as satisfying as South Pacific or King and I, let alone Oklahoma! and Carousel, and the public had a point in not wanting to be preached at for two and a half hours -- particularly when it ends with a blatant, dishonest cop-out. But Allegro has within it the essence of the "concept" musical, the musical that aims to be a complete and overwhelming theatrical experience. The last 60 years of musical theatre can be seen as a series of attempts to do what Allegro tried to do.