Symmetry Scale Guide

Stoev Symmetry Eurorack module

Scale types

Scales in Symmetry are set by choosing a scale type with the TYPE knob / CV input, and selecting pitches with the pitch-unit buttons or using the RANDOM button / CV input.

There are 10 scale types, and all but the first one are symmetrical. The pitches in symmetrical scales are evenly spread across their range and form the fundamental structure of the scale. The type of scale determines its range and number of pitches.

On top of the fundamental structure, identical sectional scales are built from each pitch of the symmetrical scale. In other words, each pitch of the symmetrical scale serves as a root of a sectional scale. The range of the sectional scales is determined by the interval between the roots of the symmetrical scale.

Sectional scales are set with the pitch-unit buttons. Their structure and range are visualized by the state of the buttons. Green color indicates that a pitch is selected, light blue – a pitch available for selection, and off indicates that a pitch is beyond the range of the sectional scale for the current scale type.

The 10 scale types are:

One root, one-octave range. This is the default scale type in Symmetry. It is ideal for creating the most widespread scales such as major, minor, all the modes, etc.

Two roots, one-octave range. This scale type divides the octave in two equal parts. For example, if we build this scale from C, then the second root will be F#, and then the scale will repeat from C an octave above, etc. The same applies to the lower octaves. Sectional scales will be built from each root.

Three roots, one-octave range. The same principle applies here as well. Starting from C the roots are: C, E, Ab, and then C an octave above.

Four roots, one-octave range. Starting from C the roots are: C, Eb, F#, A, and then C an octave above.

Six roots, one-octave range. Starting from C the roots are: C, D, E, F#, Ab, Bb, and then C an octave above. This scale type is also known as a whole-tone scale.

Twelve roots, one-octave range. Starting from C the roots are: C, C#, D, Eb, E, F, F#, G, Ab, A, Bb, B, and then C an octave above. This scale type is a full chromatic scale, and there are no sectional scales for it, since the interval between the roots is just one semitone, and there is no room for more in equal temperament.

Three roots, range of two octaves. This scale type and the rest have ranges of more than one octave, i.e. they repeat at intervals greater than the octave. Starting from C the roots are: C, Ab, E, and then C two octaves above.

Four roots, range of three octaves. Starting from C the roots are: C, A, F#, Eb, and then C three octaves above.

Six roots, range of five octaves. Starting from C the roots are: C, Bb, Ab, F#, E, D, and then C five octaves above.

Twelve roots, range of eleven octaves. This scale type goes beyond the range of human hearing. Nevertheless, it is an interesting scale type, and has its applications. Starting from C the roots are: C, B, Bb, A, Ab, G, F#, F, E, Eb, D, Db, and then C eleven octaves above.

The chosen scale type along with a particular sectional scale form a complete symmetrical scale.

Symmetrical Scale Example 1

Tonal expansion and contraction of scales

Scales in Symmetry can be expanded or contracted with < and > buttons.

Scales with one-octave range can be expanded. When such a scale is expanded the intervals between each scale degree are increased, while at the same time the pitch-units are preserved. This is achieved by rearranging the mutual positions of the pitch-units in the original scale. The number of expansions of a scale is determined by the number of pitch-units in the scale.

Scale Expansion Example

Scales with range of more than one octave can be contracted. When such a scale is contracted the positions of its roots (and the corresponding sectional scales along with them) are rearranged so that they are as close as possible.

Scale Contraction Example

In both cases the CV outputs are translated accordingly.

Play with scale expansion and contraction to get a feel for it. Although it may sound complicated at first, once you hear it in action it becomes easier to understand, and is a very useful tool.

Happy music making!