This is a section of Disney’s Fantasia that you may have never seen, as it was left out of the version that was released in 1940. Not that you probably watched it in 1940. It features “Clair de Lune” by composer Claude Debussy from his Suite bergamasque. While it was completed in time for the film, they ultimately cut it for time–without it, it still ran 125 minutes.
Later the segment was reworked and set to Blue Bayou for another production, Make Mine Music in 1946. As these things go, the original was lost for a while, but was eventually found, restored and re-set to the original music perforrmed by Leopold Stokowski and the Philadelphia Orchestra. And it can now be found on the Fantasia DVD
Fantasia was the first film released in stereo, but that was a problem because new equipment had to be installed in order to show it. Thus only 14 theaters in the US played it upon its initial release in 1940, and it lost money. Several years later it was re-released in mono and edited down to 80-minutes. It wasn’t until 1956 that it appeared again in stereo. And from that and subsequent re-releases it ranks, when adjusted for inflation, amongst the top 25 grossing films of all time.
Below is the Make Mine Music version (in Italian, set to yet another song, but it’s the only one I could find online).