The B&W movie with the manic band leader was probably "Strike Up the Band" from 1940.  The band leader was Mickey Rooney.  Per Wiki, Rooney's character wins a contest, and the prize is being allowed to lead the band in a grand finale.  A very famous, memorable quote from the film is "Take that boy on the street. Teach…

The B&W movie with the manic band leader was probably "Strike Up the Band" from 1940.  The band leader was Mickey Rooney.  Per Wiki, Rooney's character wins a contest, and the prize is being allowed to lead the band in a grand finale.  A very famous, memorable quote from the film is "Take that boy on the street. Teach…