A guided tour of some of the fascinating custom microtonal scales invented by members of the XA Discord — explained for musicians who know their theory but are new to the world beyond twelve notes
Across music history, composers and theorists have repeatedly experimented with how notes are tuned— from the ancient Greeks to Harry Partch and beyond. Today, a thriving online community called the Xenharmonic Alliance is doing the same thing, and their Discord server is one of the most active hubs for this kind of exploration.
Recently, a page on the Xenharmonic Wiki began documenting scales that were first described by members of that Discord. These aren’t scales from ancient textbooks or university theory classes — they’re the kind of thing that gets invented in a late-night brainstorming session, shared as a Scale Workshop link, and iterated on by a handful of enthusiasts over the following months. They’re informal, creative, and often genuinely surprising. Let’s take a tour.
First, a Quick Primer: What Is Going On Here?
Before we dive into specific scales, a few concepts will make everything click.
Equal temperament is what your piano uses: the octave is divided into 12 equal steps, each a semitone apart. This is convenient and flexible, but it’s a compromise — none of those intervals (except the octave itself) are perfectly pure. Your major third is about 14 cents sharp of a truly pure major third. Most people never notice, but once you start listening for it, you might.
Just intonation (JI) is the alternative: instead of equally-spaced steps, you tune intervals using simple whole-number frequency ratios. A perfect fifth is 3/2 (the higher note vibrates 3 times for every 2 vibrations of the lower note). A pure major third is 5/4. These ratios come directly from the harmonic series — the natural overtones that ring inside any vibrating string or air column. Chords in just intonation can have a striking “locked in” quality, like gears meshing perfectly.
EDOs (Equal Divisions of the Octave) generalize 12-tone equal temperament: instead of 12 equal steps, you could use 19, 31, 41, or any other number. Many of these have their own unique harmonic characters.
The scales below mix these approaches in creative ways. Some are pure JI; some are temperings (small adjustments that collapse certain tiny JI distinctions to simplify things); some are detempers (the reverse — taking an equal-tempered scale and bending its notes toward purer JI ratios). Most were designed using Scale Workshop, a free browser-based tool for building and hearing microtonal scales.
All intervals below are given as frequency ratios (like 3/2) or in cents (hundredths of a semitone; a regular semitone = 100 cents, an octave = 1200 cents).
The Bergkirsty Nordic Scale
This twelve-note just intonation scale was designed with a very specific tonal flavor: it’s tuned to center around a D–A–E frame, meaning those three notes sit in pure, beatless relationships to one another (the intervals D–A and A–E are both pure perfect fifths at 3/2). Within that frame, the other notes are colored with JI ratios, including an 11/8 — the natural 11th harmonic, which lands about halfway between an F and an F# on a standard piano, a hauntingly ambiguous interval that gives the scale its “Nordic” quality.
The complete scale, expressed as ratios from the root:
16/15–10/9–6/5–5/4–4/3–11/8–3/2–8/5–5/3–16/9–48/25–2/1
The scale is described using a colorful annotation system where each note is labeled “silver,” “blue,” or “red” based on what kind of JI ratio it represents. “Red” notes are pure Pythagorean (built from 3s and 2s only), “silver” ones involve the prime 5, and “blue” ones involve the prime 11. This mixture of prime limits — the different “colors” of harmonic complexity — gives the scale a rich and layered character.
Think of it like a painter’s palette: the Pythagorean notes give you the structural backbone (your fifths and fourths), the 5-limit notes fill in consonant thirds and sixths, and the 11-limit blue notes introduce an almost vocal, “maqam-like” quality — the kind of intonation you might hear in a singer naturally bending toward a pure overtone.
The Domin Zutsz-11 Scale
This is a ten-note just intonation scale working in the 2.3.7.11 subgroup — meaning all its intervals are built from combinations of only the primes 2, 3, 7, and 11. First described by a Discord user named Domin in July 2024, it was independently rediscovered by another user (Finky) in December 2025, suggesting the scale has something genuinely compelling about it.
33/32–7/6–77/64–21/16–11/8–3/2–77/48–7/4–11/6–2/1
What’s musically interesting here is the absence of the prime 5. In conventional Western harmony, 5 is what gives us our major and minor thirds (5/4 and 6/5). Without it, this scale has no ordinary major third — instead you get septimalintervals (from the prime 7) like the 7/6 subminor third and 7/4 harmonic seventh, plus the 11-limit neutral intervals. It’s a sound world that leans bluesy and ambiguous, with a gravity all its own.
The fact that two people independently invented this scale is a small but charming data point: harmonic space has its own logic, and sometimes multiple explorers find the same interesting landmarks.
Two pieces of music have already been written for it: Zutsz by Domin (2024) and Jam on Domin’s Zutsz-11 Scale by Nick Vuci (2024).
The FilterNashi Majorminth Scales
Discord user FilterNashi stumbled onto something intriguing: a five-note scale that is suspiciously close to the famous Japanese Hirajōshi scale, but derived from a completely different harmonic starting point — the 2.3.11.13 subgroup, using ratios involving the primes 11 and 13.
The five-note scale, in cents:
205.9–345.6–702.8–842.5–1199.7
Compare that to a traditional Hirajōshi (roughly 0–200–300–700–800 cents), and you can see the family resemblance — same skeletal shape, but each note subtly repositioned by the pull of pure 11- and 13-limit harmonics. The 702.8-cent fifth is nearly a perfect 3/2 (which would be 701.96 cents). The 345.6-cent third is closer to an 11/9 neutral third (347 cents) than to either a standard minor or major third.
FilterNashi also found a seven-note version called the “majorminth” scale. Its internal name references nicetone, a temperament that flattens the interval 352/351 to unison — meaning intervals that differ by that tiny amount (about 4.9 cents) are treated as identical. The scale is described as being in the TE tuning of the majorminth temperament.
The two seven-note versions (“paranice” scales) can be heard at links shared on Scale Workshop, and represent a nice example of how a casual observation (“this sounds like Hirajōshi”) can unfold into a whole family of related structures.
Finky6319’s Fun Jazzy Pentatonic
Sometimes a scale is exactly what it says on the tin. This one was designed by Discord user finky6319 and described simply as “fun jazzy pentatonic.”
7/6–21/16–11/8–7/4–2/1
It’s a five-note scale built entirely from the prime 7 and prime 11, living entirely in the 2.3.7.11 subgroup. The intervals are: a 7/6 subminor third (about 267 cents, noticeably flatter than a minor third); a 21/16 (about 471 cents, between a major third and a tritone); the 11/8 (about 551 cents, that ambiguous neutral tritone); a 7/4 harmonic seventh (about 969 cents, flatter than a minor seventh); and the octave.
The 7/4 is particularly significant. In jazz, the flat seventh of a dominant chord is a key color — but in 12-tone equal temperament, that minor seventh is tuned to 1000 cents, about 31 cents sharper than the pure 7/4. When you tune it purely, there’s a warm, almost vocal quality to the interval. This pentatonic sits in that sweet spot between jazz vocabulary and ancient harmonic purity.
The scale is a subset of 16afdo (the 16th mode of the arithmetic division of the octave), which means all its notes appear naturally in the harmonic series — they’re literally the overtones of a low fundamental pitch.
MrTheKing’s 11:13:16:17:19:22 Scale
This is one of the more striking entries on the page: a pentatonic scale built directly from the harmonic series, specifically from partials (overtones) 11 through 22 of a fundamental. This kind of scale is called primodal or an arithmetic frequency division.
The scale, expressed as ratios above the 11th partial:
13/11–16/11–17/11–19/11–22/11 (= 2/1)
What makes this interesting musically is that all the intervals are defined by their relationship to a single low fundamental — the 11th harmonic. They don’t have simple relationships with each other, but they all have simple relationships to that shared root. The result is a set of intervals in the 19-limit, meaning the largest prime involved is 19.
To put it another way: if you had a string vibrating at 110 Hz (the A below middle C), its 11th harmonic is at 1210 Hz. The notes of this scale are the 13th, 16th, 17th, 19th, and 22nd harmonics of that same string — pitches that are literally ringing inside the sound of the open string, just too quiet for most people to notice.
Described by mrtheking in December 2025, this scale is a nice example of how Discord members treat the harmonic series not as historical background but as a live compositional resource.
The Tristanbay Scales
Discord user tristanbay contributed several scales to the page, ranging from modest twelve-tone structures to elaborate multi-octave constructions.
The 12-tone no-5s 11-limit scale is a twelve-note scale that, as the name declares, contains no intervals involving the prime 5. That means no pure major thirds (5/4), no pure minor thirds (6/5) — the entire scale is built from primes 2, 3, 7, and 11 only. The result is a twelve-note chromatic-sized scale that sounds nothing like the familiar chromatic scale: its thirds are either the wide, bright septimal major third (9/7, about 435 cents) or the narrow subminor third (7/6, about 267 cents), with the 11-limit neutral intervals filling in between.
33/32–9/8–7/6–77/64–21/16–11/8–3/2–14/9–77/48–7/4–11/6–2/1
The 19-tone 2.3.7.17.19 scale is more ambitious: nineteen notes per octave, built from primes 2, 3, 7, 17, and 19. Including 17 and 19 as primes ventures into genuinely unusual harmonic territory — the 17th and 19th harmonics of any note are barely audible in normal acoustic contexts, and their ratios produce intervals that don’t map neatly onto any familiar scale step. This is frontier territory even within the microtonal world.
The 41fg detemper takes a completely different approach. Here, tristanbay started from 41-equal temperament (one of the most celebrated EDOs in the microtonal community for its excellent approximations of many JI intervals) and “detempered” it — meaning they bent each pitch of the equal-tempered scale toward nearby JI ratios. The guiding structure was two interlocking copies of harmonic series mode 16 (16afdo). The resulting 40-note scale is one of the most complex in the document, but it has a rigorous internal logic: every pitch is a recognizable JI ratio, and the whole structure fits together like a carefully assembled mosaic.
The Xencoder Over-23 Primodal Hirajōshi
This is a five-note scale in the spirit of the Japanese Hirajōshi, but built using primodality — a technique of taking consecutive harmonics “above” a chosen prime number as the starting partial.
The intervals:
51/46–28/23–34/23–73/46–2/1
All these ratios have 23 or 46 in the denominator — they’re built over the 23rd harmonic of a fundamental. This places the scale in the 23-limit, a region of harmonic space rarely explored even among microtonalists. The resulting scale has a vaguely pentatonic shape that echoes Hirajōshi’s characteristic moves (a large gap followed by a small step, the pull of a particular kind of minor second), but with intervals bent into alignment with the upper reaches of the harmonic series.
It’s an example of how a culturally familiar scale shape can be reimagined through an unfamiliar harmonic lens — the result isn’t Hirajōshi, but it might evoke something of the same mood, through a completely different acoustic mechanism.
The Zhea Erose Primodal Lydians
Described by Zhea Erose and recommended by Xencoder, this is a family of heptads (seven-note chords or modes) built using primodality, all with a Lydian character — meaning they feature a raised fourth degree, analogous to the #4 of a Lydian mode.
Each scale is labeled by a prime number (7b, 11b, 2e, 17b, 19b), indicating which part of the harmonic series it’s centered on. They’re described with “concordance frames” of 2:3:4 — meaning the outer skeleton of each scale (root, fifth, octave) is tuned to a pure 3/2 fifth and a pure 2/1 octave.
The first one:
7b Lydian Heptad: 14:16:18:20:21:24:27:(28) Step pattern: +2 +2 +2 +1 +3 +3 +1
These numbers are ratios within the harmonic series — the pitches of partials 14 through 28, folded into one octave. The step pattern reveals a Lydian-ish structure (equal large steps near the bottom, characteristic of Lydian’s ascending quality), but with intervals drawn from the natural overtone series of harmonic 7.
As the prime number increases — from 7 to 11 to 17 to 19 — the intervals get subtler and more complex, and the Lydian character becomes more distorted by the pull of higher harmonics. It’s a beautiful illustration of how a modal concept (Lydian-ness) can be stretched across the entire harmonic series.
Erose also contributed a family of tridecimal (13-limit) scales in various MOS templates: Lydian, Dorian, Aeolian, Mixolydian, and more exotic names like Ryonian, Azurian, and Dylathian. These are scales whose note-names reference a parallel universe of mode names developed within the microtonal community, where familiar mode shapes are given new identities when their tunings diverge far enough from the standard.
The A17Forkybest303 35edo Shower Detemper
The scale page opens with this entry, and it sets the tone perfectly for what follows: a complex detemper conceived in the shower.
The creator started from 35-equal temperament and derived a 35-note scale by taking the step sizes of several large MOS scales in nearby EDOs (23L 12s in one, 27L 8s in another, 79L 19s in yet another) and averaging them. The resulting scale has two step sizes — a large step (L) and a small step (s) — arranged in the pattern of 35L 7s with the small steps averaged out. The actual step sizes are:
L ≈ 40.94 cents, s ≈ 40.94 cents (nearly equal, but not quite)
This scale lives at the edge of something: a scale that’s almost a 42-equal division of the octave, but slightly warped by the averaging process. The full 42-note scale is listed with each pitch in cents, a long column of numbers that testifies to how seriously these community members take their self-imposed constraints and systems.
The name itself — “shower detemper” — captures something about the culture of the XA Discord: this is a space where a thought experiment in the shower gets formalized, shared, and documented for posterity.
The z4wr-Cutting Detempered Blues Scale
This one links a long chain of ideas. Discord user z4wr took a “blues scale analysis” by someone called Court B. Cutting as a starting point, then produced a detemper in the 11-limit — meaning the interval ratios involve primes up to 11.
The blues scale, in standard equal temperament, is a minor pentatonic with an added flat fifth (the “blue note”). It’s one of the most emotionally charged scales in Western music, deeply rooted in African-American musical tradition. What does it look like when you take that shape and ask: what are the closest pure JI intervals to each of these blue notes?
The answer, apparently, involves the prime 11 — because the blue note (the flat fifth / raised fourth, around 600 cents) is very close to the 11/8 (551 cents) or various other 11-limit intervals. Z4wr’s detemper bends the blues scale’s pitches toward these harmonic sweet spots, creating a version of the blues scale that “locks in” to the overtone series in a new way.
This is perhaps the entry most likely to be immediately meaningful to non-microtonal musicians: the blues scale, re-examined through the lens of pure tuning.
Why Does Any of This Matter?
The scales documented on this page range from the elegantly simple (a five-note pentatonic built from a handful of overtones) to the forbiddingly complex (a 40-note detemper of 41edo with two interlocked harmonic series). But they share something: they were all made by curious people with software tools, ears, and time — not by institutions, not for academic credit, not to fulfill a commission.
The Xenharmonic Alliance Discord is now over 2,400 members strong, and the wiki that documents its members’ work is one of the richest resources for alternative tuning theory on the internet. If any of the scales in this article caught your ear conceptually, the next step is to load up Scale Workshop in your browser and hear what they actually sound like. Many of the scales in this article have direct Scale Workshop links in the original wiki page.
Music theory has never been a finished project. Every generation finds new corners of pitch space to explore. The XA Discord is doing that exploration right now, one shower thought at a time.
Scales sourced from the Xenharmonic Wiki, a user-contributed resource documenting scales first described by members of the Xenharmonic Alliance Discord. The wiki was last edited in March 2026.
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