Microtonal Scale Generator

Explore tunings beyond 12-tone equal temperament. Generate EDO scales from 5 to 53 divisions per octave, load non-Western presets like Maqam Rast, Slendro, Pelog, and Bohlen-Pierce, or build custom scales by editing cent values. Hear each note, compare every step to 12-TET, and export your scale as a Scala .scl file — all computed instantly in your browser.

EDO Divisions

12-EDO

Scale Preset

Root Note

Root Frequency (Hz)

Show 12-TET Comparison

Tempo 100 BPM

Ascend & Descend

12-EDO (Standard)

Divisions / Period

12 steps per octave

Step Size

100.000 cents

Period Ratio

2:1 (octave)

Root

A4 = 440.00 Hz

Scale Degrees

Step	Cents	Frequency (Hz)	Ratio	Nearest 12-TET	Deviation	Play

Custom Cent Editor

How to Use the Microtonal Scale Generator

1

Choose a Tuning System

Select an EDO division (5–53 equal steps per octave) using the slider, or pick a named preset like 19-TET, Maqam Rast, Slendro, or Bohlen-Pierce from the dropdown.

2

Set Root & Frequency

Choose a root note name and its exact frequency in Hz. The default is A4 = 440 Hz, but you can set any reference pitch for your tuning.

3

Explore & Listen

View every scale degree with its cent value, frequency, ratio, and nearest 12-TET note. Click Play on individual notes or play the full scale ascending and descending.

4

Edit & Export

Use the custom cent editor to add, remove, or tweak individual steps. Export your scale as a Scala .scl file for use in synthesizers and DAWs, or copy the table data.

Understanding Microtonal Tuning

What Is Microtonal Music?

Microtonal music uses intervals smaller than the semitone (100 cents) found in standard 12-tone equal temperament. Many world music traditions — Arabic maqam, Turkish makam, Indonesian gamelan, Indian raga — have always used microtonal intervals. Western composers and experimentalists like Harry Partch, Ben Johnston, and Wendy Carlos have also explored alternative tuning systems extensively.

Equal Divisions of the Octave (EDO)

An N-EDO system divides the octave into N equal steps, each of 1200 / N cents. Standard Western tuning is 12-EDO (100 cents per step). Popular alternatives include 19-EDO (better major thirds), 31-EDO (excellent approximations of just intervals), and 53-EDO (extremely close to just intonation for many intervals).

Non-Octave Tunings

Some tuning systems do not repeat at the octave (2:1 ratio). The Bohlen-Pierce scale divides the tritave (3:1) into 13 equal steps. Wendy Carlos Alpha, Beta, and Gamma are non-octave equal temperaments designed to approximate just intervals without the constraint of octave equivalence.

The Scala .scl Format

The .scl format is the standard way to share tuning data with software synthesizers, samplers, and DAWs. It lists the number of notes and their cent or ratio values. This tool generates valid .scl files you can load directly into compatible instruments.

Frequently Asked Questions

What is EDO and how does it differ from standard tuning?

EDO stands for Equal Division of the Octave. Standard Western tuning is 12-EDO, dividing the octave into 12 equal steps of 100 cents each. Other EDO systems use different numbers of divisions — for example, 19-EDO has 19 steps of approximately 63.16 cents each, producing intervals that are impossible in 12-tone tuning.

Which EDO systems are most popular for microtonal music?

The most popular EDO systems include 19-EDO (better major thirds, used in Renaissance-inspired music), 24-EDO (quarter-tones, common in Arabic and contemporary classical music), 31-EDO (excellent just intonation approximations), and 53-EDO (nearly indistinguishable from just intonation for many intervals, historically studied in Turkish and Chinese music theory).

What are Maqam scales?

Maqam (plural: maqamat) is the system of melodic modes used in Arabic, Turkish, and Persian music. Each maqam defines a set of intervals, often including quarter-tones (approximately 50 cents) that do not exist in 12-TET. Maqam Rast and Maqam Bayati are two of the most fundamental maqamat, each with a distinctive emotional character.

What is the Bohlen-Pierce scale?

The Bohlen-Pierce scale divides the tritave (a 3:1 frequency ratio, or an octave plus a perfect fifth) into 13 equal steps of approximately 146.3 cents each. It produces a completely different harmonic landscape from octave-based systems, with its own set of consonances and dissonances.

How do I use the exported .scl file?

The .scl (Scala) format is supported by many software synthesizers and tuning utilities. You can load the file into instruments like Surge, ZynAddSubFX, Pianoteq, or use the free Scala application to convert it for other formats. Most DAWs support .scl via plugin tuning tables.

Is any data uploaded or recorded?

No. All scale computation, audio playback, and file export happens 100% locally in your browser using JavaScript and the Web Audio API. Nothing is sent to any server. The tool works completely offline once loaded.

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