She Loves Me is a lush and lovely score. I can smell the soaps and perfumes while I listen to it.
The Baker's Wife has some of the most beautiful songs, and Patti LuPone sounds amazing on the original cast recording.
As was already mentioned, Kismet is a marvelous and grandly beautiful score as is Magdelena, an earlier work by the Wright/Forrest team. It has a spectacular studio recording where Judy Kaye provides some impressive vocals alongside some amazing orchestrations. They also made a beautiful original score for Kean.
Do I Hear A Waltz? is gorgeous, I feel. The Gay Life is another lovely 1960s score, and has a wonderful Viennese sound. Highly recommended. I also think another Barbara Cook musical, The Grass Harp, has some beautiful soaring melodies.
I think the original London cast of Children of Eden is beautiful but the Papermill recording is lacking in the beauty department.
Dare I say Les Miserables? Chess? The duet "You And I" is excruciatingly beautiful as are "I Know Him So Well" and "Someone Else's Story."
With Irma you gotta do something!