And before it's too late...The Topic of the Day (in alphabetical order):
Bells Are Ringing
The Boy Friend
Damn Yankees
Fiorello! (known from the recording only)
Flower Drum Song (recording and movie)
The Golden Apple (recording only)
Guys and Dolls
Gypsy
House of Flowers (recording only)
The King and I
Li'l Abner (recording and movie)
The Most Happy Fella (recording only)
The Music Man
My Fair Lady
The Pajama Game
Peter Pan
The Sound of Music
Trouble in Tahiti (
it actually played on Broadway)
West Side Story
Whoop-Up (recording only)
Wonderful Town (recordings)
And honorable mention goes to
Saturday Night, which was scheduled to open in the 1954-55 Broadway season, but didn't.