from Cinegraphic.net:

Scorable Keyboard for Playing Visual Music

story © internetted, July 3, 2004 all rights reserved.

URL: https://www.cinegraphic.net/article.php?story=20040703113354617

This paper by Robert Emmett Mueller explains how to create "a video color music that can be scored like music and played on a standard electronic keyboard." (in .pdf).