Mary Elizabeth Hallock-Greenewalt (Sept. 8, 1871 – Nov. 27, 1950) was an inventor and pianist who performed with the Philadelphia and Pittsburgh symphonies as a soloist. She is best known for her invention of a type of visual music she called Nourathar. Thomas Eakins painted her portrait in 1903, currently in the Roland P. Murdock Collection of the Wichita Museum of Art. Biography Mary Hallock was born in 1871 in Beirut, then in Syria Vilayet, Ottoman Empire, to Samuel Hallock and Sara Tabet. After her mother began exhibiting symptoms of mental illness, eleven-year-old Mary Hallock and her siblings were sent to live with friends and relatives in the US, where she spent the remainder of her youth in the Philadelphia area. As a young adult she studied piano at the Philadelphia Conservatory of Music and then with Theodor Leschetizky in Vienna. After her return to Philadelphia Mary Hallock married Frank L. Greenewalt, a physician. The couple had one son, Crawford Hallock Greenewalt, a chemical engineer who eventually served as president of the DuPont Company. In her later years Hallock-Greenewalt resided in Wilmington, Delaware. She died in Philadelphia at the age of 79. Recordings Columbia Records released her performance of Chopin's "Preludes in E Minor, C minor, A Major" and "Nocturne in G Major" in March, 1920 (A6136). Inventions 'Color organ' The name for her art, Nourathar, was adapted from the Arabic words for light (nour), and essence of (athar). Unlike earlier inventors of color-music such as the painter A. Wallace Rimington, Hallock-Greenewalt did not produce a strict definition of correspondence between specific colors and particular notes, instead arguing that these relationships were inherently variable and reflected the temperament and ability of the performer. Her earliest attempts at creating this art entailed her construction of an automated machine where colored lights were synchronized to records. This produced an unsatisfactory result, leading to her development of an instrument that could actually be played live. Her color organ, which she named "Sarabet" after her mother, required her to invent a number of new technologies. She received nine patents from the US Patent office for them. Among these devices was a non-linear variety of rheostat, a patent that was infringed by General Electric and other companies. She sued them for infringement and won in 1934. The Sarabet went through a series of refinements between 1916 and 1934. In 1946 she published a book on