Rehearsal: The Telephone Hour (1947)

In 1947, a 27-minute, black-and-white short subject entitled Rehearsal: The Telephone Hour, was released to theaters. Originating in NBC's Studio 6B at 30 Rockefeller Plaza, the film featured, in addition to Voorhees and the orchestra, operatic bass Ezio Pinza and opera mezzo-soprano Blanche Thebom singing arias. It simulated a rehearsal of the popular program, complete with a commercial announcement, and then, near the end, segued to what was presumably the actual radio broadcast.