Harry Partch was born in 1901 and died in 1974 at the age of 73. As it happens, his Chromelodeon I – a pump organ tuned to his 43-tone just intonation scale – had 73 keys.
Chromelodeon celebrates Partch’s life and work by sounding a once-in-a-lifetime hexad (six-note chord). The very moment you press play, the year, the month, the day, the hour, the minute and the second are each used as parameters to select one of the 73 keys to play. In other words, the app “samples” the clock at any given moment and uses that moment as an ever-modulating anchor. Every second, a unique hexad is possible.
The current year (considered as the corresponding point in the 73-year cycle of Partch’s life since 1901) defines the first note of the hexad. From there, the app constructs the remaining notes of the hexad iteratively with each time component, beginning with the second and working up to the month. All remaining available keys are considered and ordered by Marc Sabat’s measure of Harmonic Radius with respect to what has already been constructed. Then the current time components act like a pointer, selecting a particular tone within that ordering. For example, if the minute is 15, the app selects the 15th item in the sorted Harmonic Radius ordering it calculated for the remaining keys.
After pressing play, a “bubble” corresponding to each note will appear in the field below the keyboard. You can drag these bubbles vertically to change their volume and horizontally to change their timbre by removing or adding partials. This allows you to control the balance of the chord. You can mute and unmute a note by “playing” its corresponding key on the keyboard.
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This work is licensed under a Creative Commons Attribution 4.0 International License.
© 2026 by Thomas Nicholson and Marc Sabat (Plainsound).