Rudolph Van Gelder was an American recording engineer who specialized in jazz. Over more than half a century, he recorded several thousand sessions, with musicians including Booker Ervin, John Coltrane, Miles Davis, Thelonious Monk, Sonny Rollins, Art Blakey, Lee Morgan, Joe Henderson, Freddie Hubbard, Wayne Shorter, Horace Silver, Herbie Hancock, Grant Green and George Benson. He worked with many different record companies, and recorded almost every session on Blue Note Records from 1953 to 1967.

An audio engineer helps to produce a recording or a live performance, balancing and adjusting sound sources using equalization, dynamics processing and audio effects, mixing, reproduction, and reinforcement of sound. Audio engineers work on the "technical aspect of recording—the placing of microphones, pre-amp knobs, the setting of levels. The physical recording of any project is done by an engineer…"