The Herbert Belar papers are composed of schematics, notes, and compositions from Belar’s work on acoustical electronics, including a music composing machine, a phonetic typewriter, and the music synthesizer, at RCA Laboratories, from 1943 to 1967. They also include schematics and reports on several projects Belar did for the military during World War II as part of a secret RCA working group called “MAD Lab.” Of special note is a 1955 letter from Robert Moog, then a student at Queens College, requesting information on RCA’s electronic music synthesizer.

Thirty-seven of Belar's lab notebooks (1948-1966) can be found in Record group 26.