https://patentbrief.org/company/firm-of-m-j-goldberg-und-sohne Plain-English explanations of patents assigned to FIRM OF M J GOLDBERG und SOHNE, newest first. en-us Sat, 13 Jun 2026 10:37:17 GMT https://patentbrief.org/patent/us/1661058/theremin-leon-theremin Leon Theremin's 1928 patent for an electronic musical instrument that generates sound based on the proximity of a performer's hands to metal antennas. Tue, 28 Feb 1928 00:00:00 GMT https://patentbrief.org/patent/us/1661058/theremin-leon-theremin