Leopold Stokowski recorded the classical music in the film at the Philadelphia Academy of Music, using the Philadelphia Orchestra (of which he was still principal guest conductor), on a multi-channel sound system, the first time one was ever used to record music in a film. The musicians seen in the film, however, were L.A.-based players doing what was called "sideline" (seen but not heard, merely miming to a prerecorded soundtrack played by others).
Deanna Durbin's vocal coach was Andrés de Segurola, a former Metropolitan Opera bass who had sung with Enrico Caruso.
Actually, there were two or three "regular" woman members of the orchestra at this time, cellist Elsa Hilger and two harpists. Further, Eugene Ormandy was the principal conductor of the Philadelphia Orchestra by 1937, not Stokowski.
On July 23, 1949, this film, double-billed with The Mikado, was revived at the Little Carnegie Theatre in Manhattan. On August 31, 1949, Universal (by then called Universal International) concluded its 13-year association with Deanna Durbin, who hadn't a new feature in release for 1949.
The one hundred men of the title are actually the Philadelphia Orchestra.