Not a trombone, but a "Valide" (half-valve, half, slide) is the instrument here being played by Brad Gowans in the March of Time film, "Night Club Boom." Gowans, featured on V-discs with the Original Dixieland Jazz Band, has leased production rights for the new horn to one of America's largest musical instrument manufacturer (from photo caption).
No date; likely between 1945 and 1950
Digitizing agency: University of Missouri--Kansas City. Library. Dr. Kenneth J. LaBudde Special Collections.
