If you listen to the OBC recording of Allegro you will probably not be able to find its merits. There is another recording, from I think an Encores! production, that is more complete and more contemporary sounding, and it might float your boat more.
Allegro is the Rodgers and Hammerstein version of a "problem play." Because of the success of Oklahoma and Carousel, the advance sales for Allegro were very high, and it obviously opened to extremely mixed reviews (which I'm sure is not surprising, as you've probably never heard of it). It tells the story of Joseph Taylor Jr from birth to adulthood. It features a singing chorus (PLEASE BRING THESE BACK!!!!!) a dancing chorus and a speaking chorus (or a Greek chorus). This was Hammerstein's baby. It is extremely complex and epic: there is nothing light hearted about Allegro. This musical is enough to understand how much influence Hammerstein had on his protege, Stephen Sondheim.
I LOVE Allegro. I don't know if I would have loved it had I just first listened to it for the first time today, but I have spent a looooot of time in the world of Allegro. We performed it in drama club when I was a freshman in high school. It was my first leading role (I played Emily). It was also how I met my first boyfriend because Show-mance is the name of the game for ol' Alisa Ledyard. I will tell you honestly that I did a massive amount of research on this play before they had auditions. It was BEFORE the internet was really a thing, too, so the research was difficult. I should really revisit it now and re-read the script. I do like the music, but I think the script has a lot more to it.
Allegro was ahead of its time in so many ways, and Oscar Hammerstein always felt that people misunderstood it. I really want the spirit of Oscar Hammerstein to know that I DO understand it, and I understood it as a 15 year old, too.
Also, this quote kills me:
"The failure of Allegro only partially tarnished the reputation of Rodgers and Hammerstein; after all, it was a very respectable flop. Yet the long-term repercussions were more serious. Never again would R&H experiment so boldly and risk losing their audience. They would continue to come up with surprising and wonderful things, but the days of radical and foolhardy innovation were over. From then on they would stick to the tried and true. Allegro marked the end of the R&H revolution."
I mean... that should never be the case. I know some of their best work was yet to come, but imagine if this show had been successful what they could have created. It hurts to think about.
Music by Richard Rodgers
Book and Lyrics by Oscar Hammerstein II