Harald Bode (1909-1987) was a predecessor of Bob Moog and Don Buchla. He is best known for the Bode Frequency Shifter; he filed a patent for this circuit in 1972 and licensed the circuit to Moog Music for sale both as a stand-alone box and as a module for the Moog Modular synthesizer series. However, his most important contribution to electronic music was a series of articles he wrote in the early 1960s extolling the virtues of transistorized circuits for audio applications; his work influenced Moog and Buchla to examine what could be done in music synthesis with solid-state devices, which led to the first synthesizers. Prior to that, Bode had built several electronic instruments which were predecessors to synthesizers; one of these was employed by Stockhausen. In the early 1970s, Bode also served as the chief engineer for Moog Music.