Mary Hallock Greenewalt received 11 patents for her “color organ,” an early form of synthesizer. She would spend the rest of her life defending them.

Mary Hallock Greenewalt received 11 patents for her “color organ,” an early form of synthesizer. She would spend the rest of her life defending them.

Mary Hallock Greenewalt always wanted to be known as an inventor. Born on September 8, 1871, in Syria Vilayet—present-day Beirut—to a Syrian mother, Sara Tabet, and an American father, she was sent at age 11 to live with relatives in Philadelphia. She began her professional life as a pianist in the Philadelphia and Pittsburgh orchestras but around 1905, when Greenewalt was in her mid-30s, she began to experiment with a new kind of instrument. It would be a feast for the senses, combining color with sound. During performances, Greenewalt would use the various pedals, switches, and keyboards on her machine—essentially an early synthesizer—to play songs that were synchronized with projected light. She called her modified organ the “Sarabet.”

Tinkering with that creation—and then defending her claims on the inventions—became her life’s work. Between 1919 and 1926, Greenewalt filed 11 patents with the United States Patent Office for inventions related to the Sarabet. In 1932, she successfully sued General Electric for copyright infringement on the rheostat, a device she patented that varied the resistance of the electricity in the Sarabet.

Greenewalt and her inventions may not be widely known to most musicians today, but they were essential to the creation of many electric instruments, in particular the synthesizer, which would revolutionize the music industry in the 1960s. Below are interpretations of four of the 11 patents Greenewalt would receive, all of which were in some way related to the development of her color organ and the principles of her work. “I want them to see,” she said of her audience, “something more beautiful than they have ever seen before.”

Patent No. 1,945,635: Sarabet (“Light Color Instrument”) (1927) Greenewalt would file four patents for the Sarabet, of which this was the final. “One object of my invention is to provide a console for a light-color instrument,” she wrote in this patent description. “Another object of my invention is to provide fluid connectors for such an instrument … and to raise or lower a current transmitting fluid about a resistor element for the purpose of increasing or decreasing its resistive action.” The Sarabet received its debut at John Wanamaker’s New York department store in 1922, so that Greenewalt could publicize her console for owners of theaters and film houses. A second console was constructed and installed at Longwood Gardens, Pierre DuPont’s botanical garden and conservatory in Kennett Square, Pennsylvania.


Patent No. 1,345,168: “Illuminating Means” (1920) This classical pedestal—shown here with a sculpture of Atlas holding the Earth on his shoulders—contained a gramophone or phonograph, which was adapted to play records and synchronize with lights of graduated tints or colors, which would then illuminate the dome. “In order that the color scheme can be developed, the rotating table which carries the record disk may be provided with leaves of translucent, colored, or parti-colored materials, overlying the source of illumination and through which the latter may shine,” Greenewalt wrote in her patent, “so that the color may be lessened or intensified, or altered in tint.”

Patent No. 1,357,773: “Rheostat” (1920) The rheostat was an essential mechanism of the Sarabet. It was an electrical device that varied the resistance of the electrical current so that Greenewalt could produce smooth fade-ups and fade-outs of light as she played. In this patent application, she describes the rheostat as “compact and substantial of a commercially practicable design; relatively simple as regards the aggregate number and arrangement of its parts, and at the same time includes a series of contact blocks and moveable contact member adapted for operation by human, mechanical or automatic power.” The rheostat would become a standard tool for electronic instruments, and when General Electric infringed on Greenewalt’s patent in 1932, she sued. At first, a judge denied hearing the case, determining that the rheostat was too complex to have been invented by a woman. This decision was overturned on appeal by Judge Hugh Morris, who described Greenewalt as “a true artist” in his decision, and she eventually won the case.

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Patent No. 1,385,944: “Notation for Indicating Light Effects” (1921)

“The object of my present invention is to provide a score comprising names, numerals, marks, symbols, hieroglyphs, or the like, constituting a chart or record sheet for denoting or interpreting a lighting sequence or succession to accompany music,” wrote Greenewalt in this patent. It involved Greenewalt’s translation of Beethoven’s 1801 “Moonlight” Sonata into a notation readable by a Sarabet player, here adapted by musician Melissa Grey.