The 24 computer-generated images (corresponding to the 24 Keyboard Etudes) were created by Ron Wallace in 1993 in the computer lab at the Massachusetts College of Art and Design in Boston.
Each of the images is a literal representation of one of the Etudes. The duration of each Etude is represented as one clockwise revolution about the center of the image. Each colored mark represents a single tone. The distance of a mark from the center signifies the value of a pitch; the higher the pitch, the greater the distance. The duration of a given tone is shown as the amount of arc subtended by its mark. The spectrum of colors represent the dynamic range of tones, with violet being very soft, followed by blue, green, yellow, orange, and red.
Below are the 24 images representing each of the Keyboard Etudes (original 1993 version).
(copyright © Ron Wallace, 1993, 2014)