On the three-disc DVD edition of The Wizard Of Oz is an audio supplement featuring takes and outtakes from the recording sessions for the film, including about eight minutes of excerpts from the prerecording session for "Over the Rainbow" which produced the version Judy Garland lip-synced to on screen. She never performed the song better. In some ways the song feels too grown-up for little Dorothy, and Garland delivers it with a maturity beyond her years, but also with an inflection of simplicity and innocence that makes it work on every level in the film. The commercial recording of the song she did for Decca, which became a huge best-seller, is far less emotional and delicate.
In later years, as a concert performer, Garland turned the song into a bittersweet anthem for lost dreams, but it works best from the near side of hope, where the dreams that you dare to dream really do come true.
Genius filmmaker Louis B. Mayer insisted that the song be removed from the film, because it slowed things down, but Arthur Freed put his job on the line to keep it in, and he prevailed.