July 18, 1939: The song “Over the Rainbow” is restored for a sneak preview of The Wizard of Oz in Westwood, CA. Producers had cut it from the version shown to a Pomona audience the month before because they felt it slowed things down.
The Harold Arlen tune was put back in by demand of Arthur Freed, who went on to run MGM’s signature musical unit. (From Edward Jablonski’s Harold Arlen: Rhythm, Rainbows, and Blues.)
“Over the Rainbow” ranks first in the American Film Institute’s tribute 100 Years…100 Songs (2004).
To give the producers their due, another cut they made improved the movie, dropping a song called “The Jitterbug” and a scene in the original script featuring a series of musical contests:
A spoiled, selfish princess in Oz had outlawed all forms of music except classical and operetta and went up against Dorothy in a singing contest in which her swing style enchanted listeners and won the grand prize.