Home | Vaudeville | A Night at the Opera
Before filming, Irving Thalberg send the brothers on the road to test out their routines. The tour visited Salt Lake City, Seattle, Portland and San Francisco. Morrie Ryskind was backstage to record which gags worked. Allen Jones was in the cast and various other opera singers were appearing. More information about the Salt Lake City show can be found here.

Kudos to David C. for finding the Salt Lake city link