Understanding Colour Properties in Orphere: Brightness, Dissonance, Complexity, and More

Composer at a piano

When you browse scales or chords in Orphere, each one comes with a set of colour properties: quality, brightness, dissonance, unevenness, complexity, uniqueness. These aren’t decorative. They describe the harmonic colour of a scale or chord, and they’re searchable and filterable, designed to help you find what you’re hearing in your head. This post explains what each one measures and how to use it.

Properties at a glance

Not every colour property applies to both scales and chords. Here’s where each one lives:

Property	Scales	Chords
Quality	Yes	Yes
Brightness	Yes	Yes
Dissonance	No	Yes
Unevenness	Yes	No
Complexity	Yes	Yes
Uniqueness	Yes	No

The reason for the differences is structural. Unevenness describes how evenly notes are distributed across an octave, which only makes sense for scales (chords don’t have step patterns in the same way). Dissonance measures the acoustic tension between chord tones sounding simultaneously, which is important for chords but not scales. Uniqueness measures how far a scale’s degrees sit from its modal reference triad on the circle of fifths, which is inherently a scale-relevant concept.

Quality

Quality is the most basic colour property. It classifies every scale and chord as major, minor, or other based on the third degree. If the third is natural (3), the quality is major. If it’s flat (b3), the quality is minor. If there’s no third at all, the quality is other.

This single degree shapes the overall character more than any other. A major quality sounds bright and resolved. A minor quality sounds darker and more introspective. Quality is the first filter most composers reach for, and it pairs well with every other colour property.

When to use it: Start here to narrow your search by broad character before refining with brightness, complexity, or other properties.

Brightness

Brightness measures how raised or lowered a scale’s or chord’s degrees are overall. It’s calculated by summing the alterations across all degrees: each sharp adds to the total, each flat subtracts.

For scales, this places modes on a spectrum. Among the diatonic modes, lydian is the brightest (it has a raised 4th) and locrian is the darkest (five of its seven degrees are flattened relative to major). The full ordering from bright to dark is: lydian, ionian, mixolydian, dorian, aeolian, phrygian, locrian.

For chords, brightness works the same way. A major triad (degrees 1, 3, 5) is brighter than a minor triad (1, b3, 5) because the natural third scores higher than the flat third.

When to use it: You’re scoring a scene and the current harmony feels too heavy. Filter for chords or scales with higher brightness to find options that lift the mood without changing the tonic. Or you want to darken a passage gradually: sort by brightness and step down one level at a time.

Dissonance (chords only)

Dissonance measures the acoustic tension between the tones in a chord. Each interval has a dissonance value derived from its frequency ratio: simpler ratios (like the 3:2 of a perfect fifth) are more consonant, while more complex ratios (like the 16:15 of a minor second) are more dissonant. The chord’s total dissonance is the sum of the dissonance values across every pair of tones.

A major triad scores low because its intervals (major third, minor third, perfect fifth) all have relatively simple ratios. A chord with a minor second or major seventh between voices scores higher. Clusters and dense extended chords push the value up further.

When to use it: You want to control tension across a progression. If a passage needs to build towards a climax, look for chords with progressively higher dissonance. If you need a moment of resolution, filter for low dissonance. This is also useful for orchestration: a chord that looks complex on paper might actually have low dissonance if its intervals are acoustically clean.

Unevenness (scales only)

Unevenness measures how evenly the notes in a scale are distributed across the octave. It’s calculated as the standard deviation of the step sizes in the scale’s interval pattern.

A whole tone scale has zero unevenness because every step is 2 semitones. The major scale scores relatively low because its steps (2-2-1-2-2-2-1) only vary between 1 and 2 semitones. The harmonic minor scale scores higher because of the augmented second (3 semitones) between the 6th and 7th degrees, which creates a noticeable gap.

When to use it: Unevenness affects how a scale feels melodically. Low unevenness tends to produce smooth, flowing lines. High unevenness creates scales with characteristic leaps or gaps, which can sound exotic or dramatic. If you’re writing a melody that needs to move evenly, filter for low unevenness. If you want something with a distinctive intervallic fingerprint, look for higher values.

Complexity

Complexity measures how common or unusual the intervals between a scale’s or chord’s tones are, using a concept called tonal interval classes.

A tonal interval class (TIC) represents how many steps around the circle of fifths it takes to reach a given interval. A perfect fifth is one step (TIC 1), making it the most common interval in tonal music. A tritone requires six steps (TIC 6), making it rare. Complexity averages the TIC values across all pairs of tones, weighted by how frequently each interval appears.

Scales and chords built primarily from perfect fifths, fourths, and major/minor thirds score low. Those containing tritones, augmented intervals, or unusual combinations score higher.

When to use it: Complexity tells you how tonally tense the intervals within a chord or scale are. A chord with high complexity contains intervals that are far apart on the circle of fifths, which creates a sense of harmonic tension even if the chord isn’t traditionally “dissonant”. Low complexity means the intervals are familiar and grounded.

Uniqueness (scales only)

Uniqueness measures how far a scale’s degrees are from the fundamental tones of its mode. For major-quality scales, the reference point is the major triad (1, 3, 5). For minor-quality scales, it’s the minor triad (1, b3, 5). The calculation sums the tonal interval class distances between each degree and each reference tone.

A standard major scale scores low because most of its degrees are closely related to the 1, 3, and 5. A double harmonic major (with its b2 and b6 alongside natural 3 and 7) scores much higher because those altered degrees sit far from the reference triad on the circle of fifths.

When to use it: Uniqueness is a good proxy for how “exotic” a scale will sound to ears trained in Western tonal music. It’s particularly useful when you’re searching for a scale that has a specific quality (major or minor) but want to control how conventional or unusual it feels. Low uniqueness gives you the familiar modes. High uniqueness takes you into territory like neapolitan, double harmonic, and chromatic scales.

Note that complexity and uniqueness measure different things. Complexity is about the intervals between tones, while uniqueness is about the degrees themselves. A scale can have common degrees but unusual intervals between them (high complexity, low uniqueness), or rare degrees that happen to form simple intervals (low complexity, high uniqueness).

Using colour properties together

The real power of these colour properties comes from combining them. A few examples:

“Something dark but smooth”: Filter scales for low brightness and low unevenness. You’ll get modes like aeolian and dorian rather than harmonic minor, which has a large gap between its 6th and 7th degrees.
“A tense chord that resolves cleanly”: Find chords with high dissonance for the starting chord and look at chords with low dissonance for the subsequent chord. The contrast creates the resolution.
“An exotic major scale”: Filter for major quality and high uniqueness values. Familiar scale types will be filtered out, leaving the unusual ones.
“A simple, consonant voicing with colour”: Filter chords for low dissonance and 4 tones. You’ll get clean seventh chords without the tension of dense extensions.

Every colour property in Orphere is designed to describe something you can hear. The numbers aren’t abstractions. They correspond to real perceptual qualities: how bright something sounds, how tense it feels, how familiar or foreign the intervals are. The filters let you search for those qualities directly, so you spend less time pondering and more time writing.