An early short to demonstrate the new movie process of Cinemascope, this short is nicely shot in Technicolor, and the orchestra is shown with some discrimination. Obviously the person who shot it concentrated on what to photograph at different points. They are playing Otto Nicolai's overture for THE MERRY WIVES OF WINDSOR (a nice piece of music, from a forgotten opera - Verdi and Boito's later opera FALSTAFF is more frequently revived). The music is very familiar, as one of the pieces of classical repertory that was used again and again in films (including cartoons) like Von Suppe's Light Cavalry Overture. Turner Classic films showed it as a "One Reel Wonder" tonight about 7:40 - 7:50 P.M.
If one studies it, besides some nice shots of Johnny Green conducting the opera, look at close ups of the players who are momentarily at the center of the score. For example the first oboist about halfway through it, or the cymbalist towards the end. Those shots are why I think the person shooting this short was studying the orchestra while it rehearsed, to note who to concentrate the camera on momentarily.
Whatever the original reason, it is a pleasant concert piece - worth watching or listening to at least once.