Prod. 2272 - Symphony Hour
Layout by Harold Miles, who was also live action set designer.
Date of this final draft 11/3/1941, released 3/20/1942.
The attack on Pearl Harbor was inbetween those dates...
John McLeish was the voice of the announcer, with animation by Ken Muse, Marvin Woonward, Jim Moore, Bernie Wolf, John Elliotte, Ed Love and Les Clark, among others. Re-use from Society Dog Show...
And there is even a scene by the director!
The film is on Disney Treasures DVD: MM in Living Color Vol. 2.