The opera Four Saints in Three Acts is in four acts and about as many as seven saints. (It's difficult to give an exact number of protagonists due to the show's incomprehensible style.)
The dance number "Bolero d'Amour" from Follies is a tango.
Shakespeare's Twelfth Night does not take place on Twelfth Night, nor is it even mentioned in the play. (It was written for Twelfth Night). The play's full title is "Twelfth Night or What You Will", which amounts to a Shrug of God on Shakespeare's part: if you've got a better title, by all means use it.
The main character from Miss Saigon, Kim, doesn't actually win the Miss Saigon title at the beauty pageant that opens the musical.
The finale song "Letting Go" from some productions of The Musical of Jack Heifner's Vanities is not necessarily a farewell song, but about not letting go of one's best friends.
Lowe Hite And Stanley, a post-Vaudeville act, consisting of a giant, an averaged-sized guy, and a midget. Henry Hite (Real name Henry Mullens) was indeed the giant, but Tommy Lowe (real name Roland Picaro) was not the midget—he was the averaged-sized man. The midget was Stanley Ross.
The solo instrument in "Cornet Man" from Funny Girl is a trumpet, not a cornet.