Illumikey: A Dynamic Musical Display

by Eric von Bayer (C) Copyright 2015

Illumikey is an experimental display designed to be used with the Haken Continuum or keyboards. A strip of independently changeable RGB LEDs is placed along the back/upper edge of the fingerboard/keybed to provide various forms of feedback to the player.



Scale Mode

Scale mode provides a simple cyclic pattern of 12 colors to back each octave. This enables the player to represent scales to the player. This mode is mostly inspired by the LinnStrument and Ableton Push. Currently it just is a 2 color pattern, eventually I'll add a separate color for the tonic.

Harmonic Mode

Harmonic mode attempts to map the harmonic nature of notes based on what is already playing. To do this MIDI is accepted from multiple sources and analyzed for note ons, note offs, pitch bend, sustain, sustenuto, reset all controllers, and all notes off. These MIDI events are combined with per port preferences for transpose and pitch bend range to compute the pitch of all notes that should be playing.

Once these notes are mapped, a simple algorithm is applied to each note. First, all notes are rounded to the 12-note scale and all are displayed as white. Any notes that are ±2 or ±1 semitones are mapped as "inharmonic" and colored red. Any notes that are ±11 and ±13 are mapped as "partially inharmonic" and marked as yellow (though commonly used in 7th chords.) All other notes are considered "harmonic" and marked as green.

This simple display is very effective in displaying content from multiple surfaces/keybeds and potentially sequencers to warn of sour notes. Eventually some degree of persistence might be useful, but it may prove hard to discriminate parts of a continuing musical phrase from a key change. This could easily render the display at least temporarily useless.

Analysis Mode

Though analysis mode is not yet implemented, I am looking to take a FFT of audio and render a color based amplitude of the frequencies centered on each key. I expect the spectrum will need to be normalized for relative energy to be very useful. The hope would be for the primaries and the harmonics to be readily visible and the noise components though visible to be easily discernible.

Technical Details

Illumikey is comprised of the following pieces:

Contact Information

If you wish to contact me, please use illumikey at ericvonbayer dot us.