1894-1981
If you look at the list of Broadway productions Bennett orchestrated between the 1920s into the 60's, one realizes the man was a major talent. He certainly made Cole Porter, George Gershwin, Irving Berlin, and Richard Rodgers look like geniuses.
Like many entertainment musicians, Bennett has a wealth of concert music which hasn't seen the light of day. My guess is it isn't a matter of quality; rather his star shone in other avenues.
The few dedicated recordings afforded to Bennett alone, at least the ones away from the Musical Theatre stage, are mostly for concert band, although there is some orchestral music out there too. His Symphonic synthesis of Porgy and Bess is still popular.
Lest I forget, don't mix up Robert Russell Bennett with Richard Rodney Bennett, another composer involved in entertainment music with a wealth of concert hall compositions to his name.
Recordings and reviews currently on hand (Click below to visit):
1987: A Festival of Carols & Many Moods of Christmas
1999: Abraham Lincoln & Sights and Sounds
2016: Old American Dances