Chord from Scale module

This module automatically builds a chord on a selected degree of a scale.

Given either a manually set or voltage controlled degree and an S-Poly scale signal it constructs an S-Poly chord signal with however many notes are set by the NUM NOTES control.

A degree I chord with 3 notes from a C major scale

It also has a handy BASS OUT socket that outputs the lowest note in the chord as a 1 V/Octave CV signal.

The Chord From Scale module provides an alternative mechanism for producing chords to the Chord and Diatonic Triads modules. There is an overlap in functionality – so each module can produce some of the same chords as the other modules. Each module has its own strengths and weaknesses.

The basic idea is that the SCALE IN socket is fed an S-Poly scale signal from a Major Scale, Minor Scales or Modal Scales module – each of which produce scales consisting of seven notes.

The module then selects a starting note in the scale depending on either the setting of the DEGREE knob or a control voltage if one is connected.

It uses this starting note as the root of the chord (this note is also available via the BASS OUT socket). Then depending on how many notes are selected using the NUM NOTES knob more notes from the scale are added to the chord. Each new note is two steps up the scale from the last. This is an interval of a third in standard scales so we end up with diatonic chords built of stacked thirds.

In some scales a particular step may be a major interval, in another it might be a minor interval. These differences in step sizes are what give each scale (and its diatonic chords) a characteristic feel.

NUM NOTES can be 1, 2, 3, 4 or 5. A setting of three produces diatonic triads. A setting of 4 produces diatonic 7th chords and a setting of 5 produces diatonic 9th chords.

Constructing a degree III diatonic 7th chord from a Dorian scale in the key of C

If a cable is plugged into the CV IN socket then the DEGREE knob no longer has any effect. Instead the voltage fed to this socket determines the degree of the chord…

less than 0.5 I
0.5 to just under 1.0II
1.0 to just under 1.5III
1.5 to just under 2.0IV
2.0 to just under 2.5V
2.5 to just under 3.0VI
3.0 and aboveVII
Mapping between control voltage and degree

As Adroit scale and chord signals are interchangeable this module can also be fed with a chord signal instead of a scale signal. One application for this is to use CV IN and BASS OUT to extract a particular note from a chord – you could use this to build something like a custom arpeggiator.

Other chord modules.