Bullock was mostly associated with the ARC group of record labels (Melotone, Perfect, Banner, Oriole, Romeo).
[2] Bullock belonged to a select group of mostly freelance vocalists who sang the vocal refrains on hundreds of New York recording sessions, which included Smith Ballew, Scrappy Lambert, Irving Kaufman, Arthur Fields, and Dick Robertson.
(All of the above had records also issued under their own name, and in case of Ballew, actually had a working orchestra for a couple of years.)
[2] He began working regularly as a studio musician in the late 1920s and in the 1930s he sang with the bands of Duke Ellington, Luis Russell, Cab Calloway, Bunny Berigan, Bill Coleman, Jack Teagarden, Tommy Dorsey, Jimmy Dorsey, Joe Venuti, and Eddie Lang.
The 1942-44 AFM recording ban essentially ended Bullock's career,[2] and he retired from the music business in 1942.