Wikipedia
The chordboard is an electronic musical instrument based on software, and played by a keyboard controller. One implementation is a set of four MIDI keyboards arranged vertically. The patent for this musical technology specifically identifies the seven chords that exist for each key signature, and how these key signatures can be selected at any time while playing the instrument to achieve a key signature change, and thus an instant change in chords. In every key signature there are seven chords, and each of these chords are identified on the chordboard as follows (signified by Nashville Notation):
- I chord is major tonality, referred to as ROOT CHORD
- ii chord is minor tonality, referred to as SUPER TONIC CHORD
- iii chord is minor tonality, referred to as MEDIANT CHORD
- IV chord is minor tonality, referred to as SUB-DOMINANT CHORD
- V chord is minor tonality, referred to as DOMINANT CHORD
- vi chord is minor tonality, referred to as SUB-MEDIANT CHORD
- vii chord is minor tonality, referred to as LEADING TONE CHORD
Pressing a key on any one of the chordboard's four keyboards sounds a single note within the chord zone. Each key plays only one note. To play a chord, the musician plays two or more keys, similar to a piano.