The color organ is the recurring dream of playing light. Castel proposed the ocular harpsichord in the 1720s; Rimington patented and performed on a projection instrument in the 1890s and gave the dream its English name; Scriabin scored for a keyboard of light in 1910; Wilfred’s Clavilux abandoned music entirely for pure light performance.
The 1970s recycled the name for something humbler: the light organ, a filter box flashing lamps with the stereo, which is why searches for the term surface vintage disco hardware next to art history.
Every audio-reactive visualizer is a descendant. The instrument stopped being furniture and became software; the ambition, sound made visible in performance, never changed.