Everything you need to start composing, performing, and experimenting with microtones
If you've ever heard the haunting slides of a Turkish saz, the rich shimmer of Indonesian gamelan, or the otherworldly harmonics in a piece by Harry Partch, you've heard microtonality at work. As a musician who already understands chord progressions, intervals, and scales, you're actually better equipped than most to dive into this world — because microtonal music isn't about throwing out everything you know. It's about expanding it.
This guide is a comprehensive tour of the software available for making microtonal music in 2025, organized by category so you can find exactly the tools you need. Whether you want to dip your toes in with a browser app or go deep with a full production setup, there's something here for you.
A Quick Primer: What Is Microtonal Music?
Before we get to the software, a few concepts worth knowing.
Western music is built on 12-tone equal temperament (12-TET or 12-EDO) — the octave is divided into 12 equal semitones. This is a practical compromise: it lets instruments stay in tune across every key, but it slightly detunes nearly every interval from its "pure" mathematical ideal. A perfect fifth in 12-TET is 2 cents flat of the true 3:2 ratio. A major third is 14 cents sharp of a pure 5:4. You probably don't notice these differences consciously, but your ear does.
Microtonal music explores tuning systems beyond this 12-note grid. The main approaches include:
Equal Divisions of the Octave (EDOs): Just like 12-EDO divides the octave into 12 equal parts, you can divide it into 19, 24, 31, 53, or any other number. 19-EDO makes major thirds purer and feels close to familiar. 31-EDO was advocated by 16th-century theorist Nicola Vicentino and produces beautiful extended harmonies. 72-EDO is fine-grained enough to approximate nearly any tuning system.
Just Intonation (JI): Intervals are tuned to exact small-integer frequency ratios — a 3:2 perfect fifth, a 5:4 major third, a 7:4 harmonic seventh. This produces intervals that "lock in" with a distinctive resonance. Just intonation was the basis of tuning before equal temperament took over, and it remains central to xenharmonic exploration.
Regular Temperaments: Mathematical systems that "temper out" certain commas (tiny intervals) to create practical scales with good approximations of JI intervals. Meantone temperament, which underlies the historical keyboard tunings of Bach's era, is one example. Miracle temperament, Porcupine, and hundreds of others are catalogued on the Xenharmonic Wiki.
Now, to the software.
Part 1: DAWs — Which One Should You Use?
Your Digital Audio Workstation is your central hub. Not all DAWs are created equal when it comes to microtonality, and the differences matter a lot. The core challenge is this: most DAWs and most soft synths assume you're working in 12-TET. Getting them to play other tunings requires either native support, clever routing tricks, plugin-based solutions, or some combination of all three. The Xenharmonic Wiki maintains a detailed DAW comparison page which goes deep on every major option.
Here's the landscape:
Reaper is consistently the top recommendation in the microtonal community. It has extremely flexible MIDI and audio routing, no problems handling sysex messages or multiple MIDI channels (both of which are essential for certain retuning workflows), and the piano roll can be visually customized to show more or fewer than 12 notes per octave. You can even remap QWERTY keyboard keys to any MIDI note. The Alt-Tuner plugin (more on this below) was specifically designed with Reaper in mind. It's also inexpensive — the discounted license for non-commercial use is very affordable — and the demo gives you full access to all features including saving and loading.
Bitwig Studio is a strong second choice, particularly if you want native microtuning without relying entirely on third-party plugins. Bitwig's built-in synthesizers support per-note pitch-bend via MPE (MIDI Polyphonic Expression), which is one of the modern approaches to microtonality. Its piano roll lets you detune individual notes with an intuitive interface. Bitwig runs on Windows, Mac, and Linux, which is a rarity.
FL Studio has a useful per-note "fine pitch" setting in its piano roll, which works with most of its own bundled plugins (Flex, Harmor, Direct Wave sampler, and others). For external VST plugins, you'll need tuning files instead. It doesn't handle sysex, but its internal routing makes channel-based retuning work smoothly.
Ableton Live has historically been the worst major DAW for microtonality due to how it merges MIDI channels internally and filters out sysex messages. However, Live 12 introduced some tuning system features, and third-party plugins like MTS-ESP (see below) have made it more workable. If Ableton is where you feel at home, you're no longer locked out of microtonality — but you'll need extra tools.
Logic Pro has a global tuning setting and can import .scl (Scala) files for its built-in instruments. The catch: it only understands 12-note-per-octave scales with deviations of no more than ±100 cents from 12-TET, and you can only have one tuning per song. Good for dipping a toe in; limiting for serious exploration.
Reaper (worth repeating) also shines on Linux alongside Bitwig, making it the go-to for open-source-oriented musicians.
Part 2: The Scala Format and Why It Matters
Before going further, you need to know about Scala. Created by Manuel Op de Coul, Scala is both a software application and, crucially, a file format (.scl) that has become the universal standard for describing tuning systems. A .scl file is a simple text file listing the intervals of a scale — you can open one in Notepad and read it. The Scala software ships with a library of over 5,000 historical, theoretical, and experimental tunings.
Alongside .scl files, the .kbm (keyboard mapping) format specifies how those scale degrees map onto MIDI note numbers — which physical key plays which scale tone, and where the scale repeats. The combination of .scl and .kbm gives you complete control over any tuning on any instrument that supports them.
Most microtonal software either imports .scl files directly or has its own format it can convert to/from .scl. Learning to work with Scala files is probably the single highest-return investment of your time in this space.
Part 3: Composing Software
These are dedicated environments for writing microtonal music, ranging from code-based to graphical.
Alt-Tuner by Kite Giedraitis is a tuning plugin that handles adaptive tunings, on-the-fly retuning, and scale analysis. It integrates particularly well with Reaper and FL Studio. "Adaptive tuning" means it can tune chords to pure JI ratios in real time, so your music automatically locks into beatless fifths and thirds as you play.
Csound is one of the oldest and most powerful computer music environments, with no restrictions on xenharmony whatsoever. If you can describe it mathematically, Csound can synthesize it. The learning curve is steep — it's a programming language — but its power is unmatched.
Blue is a graphical composition environment and frontend for Csound with Python-based scripting. It makes Csound considerably more approachable while keeping its flexibility.
MicroCsound is a Python-based frontend specifically designed for microtonal composition with Csound. There's a tutorial available on the Xenharmonic Wiki.
Rationale is an open-source just intonation sequencer built on Csound and Python, focused specifically on JI composition.
Jird takes a unique approach: it's a language for writing music where you express frequencies, durations, and volumes directly as ratios. If you're comfortable thinking in JI terms (3/2 for a fifth, 5/4 for a major third), Jird makes that extremely direct.
SuperCollider is a professional programming language for sound synthesis and algorithmic composition with no restrictions on pitch whatsoever. It has an active community, extensive documentation, and is used in both academic and experimental music contexts. Like Csound, it requires learning a programming language, but the payoff is total freedom.
Mutabor is an open-source dynamic microtuner with a flexible scripting language designed for musicians rather than programmers. It supports both mutable (adaptive) and static scales and tunings with a GUI.
WereSoCool is a language specifically for composing microtonal music — its name is both whimsical and accurate.
Schismata is a compositional tool for any user-defined tuning that supports polyrhythms, real-time tuning changes, sliding notes (glissandos), and instrument design all in one package.
pxtone collab is a "multiplayer music editor" — a collaborative tracker-style tool with pitch snapping from 7-EDO to 36-EDO (and beyond if you compile from source), free pitch control, and fine tuning.
SoundModeler is a free sound modeling application that exports audio files and Halion multisamples, transposing notes according to user-selected temperament: equal, Pythagorean, just, or meantone 1/4 comma.
Melodyne is the commercial audio software famous for its pitch editing. While not a microtonal composition environment per se, its DNA direct note access and tuning analysis functions can be used to analyze and edit microtonal content in recorded audio.
TiMidity++ is a MIDI-to-audio renderer that can handle microtonally-tuned files.
Xenharmlib is a Python library for music theory exploration covering microtonality, diatonic set theory, and non-standard notations. Useful if you're a programmer wanting to work algorithmically with tuning systems.
Browser-Based Composing Tools
Xenpaper is a text-based microtonal sequencer — think of it as a notepad where you write musical ideas using a simple notation and share the link. No installation required. Excellent for quick experiments and sharing ideas with others.
forbidden-music is a browser-based piano roll that is not quantized vertically, with tuning "snaps" you can use to create harmony — a genuinely novel approach to composition.
Nondiscrete Piano Roll by Joaquín Aldunate lets you compose microtonal pieces in a custom JI or tempered tuning with a visual piano roll interface.
Part 4: Software Instruments
These are playable synthesizers, samplers, and instruments with built-in microtonal support.
Microsynth is a microtonal soundfont synthesizer for macOS and Windows. It plays back soundfonts (the .sf2 format used by General MIDI) with user-defined tunings.
SunVox Modular Music Studio is a modular synthesizer with a pattern-based sequencer (tracker-style), available for desktop (free) and mobile devices (around $6). It's one of the most fully-featured free microtonal instruments available and runs on nearly every platform including iOS, Android, Windows, Mac, and Linux.
Sonic Pi describes itself as "The Live Coding Music Synth for Everyone." Beyond live coding, you can record to WAV, and microtonal capabilities are provided by adding decimals to MIDI note numbers.
Terpstra Keyboard is a cross-platform web app that maps any tuning in Scala format onto a generalized hexagonal keyboard layout. Settings are stored in the address bar for easy sharing. The hexagonal layout is significant: isomorphic keyboards keep chord fingerings the same in every key regardless of the tuning system.
Wickisynth is a browser-based tuning demo synthesizer using the Wicki-Hayden isomorphic key layout.
Xenharmonic Keyboard is a Windows-only isomorphic microtonal MIDI keyboard controller.
Adjustable Grid Web Synth is a browser-based synthesizer supporting EDOs, non-octave tunings, and JI, with adjustable base frequency and adjustable key size via rows/columns input.
Frequency Explorer is a browser-based synthesizer and sequencer with precisely configurable musical scales and harmonic spectra — notably, it lets you link the timbre of the instrument to the scale, which is a deeper concept related to harmonic entropy and why certain tunings sound more consonant with certain timbres.
Dynamic Tonality synthesizers and sequencers are freely available and embody a specific compositional concept: the idea that timbre and tuning can be continuously varied together.
Online 19-EDO Keyboard — a browser-accessible keyboard specifically for 19-tone equal temperament.
Rational Keyboard — a browser-based JI keyboard where keys grow in size in proportion to the harmonic complexity of the note. A beautiful visualization tool as much as an instrument.
Microtonal Fabric is a web-browser-based microtonal music platform providing a framework for building universal or customized microtonal keyboard instruments, including remote teaching possibilities.
Offtonic Microtonal Synthesizer is a JavaScript browser app for experimenting with tunings.
Chameleon is a customizable MIDI controller interface that can be used to create virtual microtonal keyboards.
Mobile Apps (iOS)
AudioKit Synth One is a free iPad/iPhone touch-to-play synthesizer with customizable layout and scales that can import scales directly from Wilsonic (see below). Free and open source.
GeoShred is an iPad/iPhone touch-to-play app with customizable layout and scales. It uses a surface similar to a guitar fretboard and has excellent MPE support.
Droneo is an 8-voice polyphonic droning iPhone app that defines intervals in just ratios, equal divisions of an interval, or interactively with a tone spiral. Focused on creating microtonal drone textures.
ThumbJam is an iPad/iPhone touch-to-play app with customizable layout and scales that can open any .scl (Scala) file directly.
Orphion is another iPad/iPhone touch-to-play app with customizable layout.
Wilsonic is an iPad/iPhone app for exploring the scale systems of Erv Wilson, the highly influential theorist who developed concepts like MOS (Moment of Symmetry) scales, combination product sets (CPS), and much more. It's a remarkable archive of Wilson's work in playable form.
Part 5: Tuning Manipulation Software
These are the backbone of many microtonal workflows: tools for creating, converting, and applying tuning files.
Scala (by Manuel Op de Coul) is the de facto standard. The software itself can generate, analyze, convert, and apply an enormous variety of tuning systems. The .scl file format it uses is the lingua franca of microtonal software. If you do nothing else on this list, download Scala and explore its built-in library of thousands of tunings.
Universal Tuning Editor by Hpi is the modern successor to Scala for many practical workflows. It can create, import, edit, convert, and map tunings to any keyboard geometry, and retune compatible soft synths in real time. Supports an impressive range of file formats and tuning standards.
Scale Workshop (by Lumi Pakkanen) is a free browser-based scale creation tool. You can build scales, play them via QWERTY keyboard, and export .scl and .kbm files. It has become one of the most-used tools in the community for sharing and exploring scales. A legacy version is also available for older workflows.
Tune Smithy by Robert Walker is a comprehensive Windows tuning utility with a very long history in the microtonal community.
tune is a command-line tool for exploring musical tunings and creating synthesizer tuning files for microtonal scales.
Scalemap provides drop-in microtonal note-to-frequency mapping functionality for C, C++, and JavaScript — useful if you're building your own software.
Temperament Evaluator by Flora Canou is a set of Python scripts for computing Tenney-Euclidean (TE) tunings, badnesses, optimal patent vals, and other regular temperament metrics. Essential for mathematically rigorous temperament analysis.
ChucK is a digital audio programming language from Princeton University with arbitrary tuning support. miniAudicle is its companion development environment.
Superparticular Samchillian is open-source tuning manipulation code built on miniAudicle, by Leon Gruenbaum and Jacob Barton, implementing the Samchillian concept (a relative-pitch instrument).
Browser-Based Tuning Tools
The xenharmonic community has produced a remarkable ecosystem of browser-based calculators and tools. Here are the major ones:
XeTune by John Valentine is a full-featured tuning manipulation web app.
Xen-calc is an interval calculator that translates between ratios, cents, FJS (Functional Just System) notation, color notation, and more.
Scale Workshop (mentioned above, worth repeating because its browser-based nature makes it particularly accessible).
Color Horizons by Jon Lervold is a scale generator and synthesizer.
Edjiruler v0.0.1 visualizes JI intervals close to equal divisions of whole numbers.
Harmonic Entropy Calculator by Mike Battaglia shows interactive harmonic entropy curves — a way to visualize the perceived consonance of intervals.
JI Scale Interval Calculator shows a list of all JI intervals in a given JI scale.
Music Calculators by Jeremiah Goyette: a collection of useful tools.
Music Maker Calculator by Ambient Esoterica: a collection of xenharmonic gadgets.
Rank 2 Regular Temperament Generator by Scott Thompson generates rank-2 regular temperaments from generator and period inputs.
Scala2MTS by Olle Holmberg converts Scala files to MIDI Tuning Standard SysEx format.
ScaleCircle by Nick Vuci generates a circle diagram of any scale with a period (JI or tempered).
Temperament Calculator by Sintel.
Temperament Finder by Graham Breed.
Cents to Ratio Calculator by Sengpiel Audio (also converts to other units).
Uniform mapper — finds uniform maps corresponding to integer and non-integer EDOs.
UnTwelve Tools — UnTwelve's online suite, including MOS visualization, Stern-Brocot Tree visualization, and an interval calculator.
Untwelve.org interval calculator — shows linear fraction and EDO fraction expansions.
Xenharmonic Wiki interval calculator — online interval calculator with linear fraction and EDO fraction expansions.
Tonespiral — listen to harmonics visualized as a spiral.
The Sound of Color — listen to colors sonified as pitches in the audible range.
Projective Tuning Space Interactive Application — a geometric visualization tool for tuning relationships.
Desmos-Based Tools
The Desmos graphing calculator has become a surprisingly powerful platform for microtonal visualizations. Notable examples include:
- Diatonic Scale Explorer — visualize the diatonic scale with different sizes of fifths
- Octave harmonics proximity to EDO (circle) — visualize how well an EDO approximates harmonic series members
- Patent val monzo mappings — visualize how temperaments map primes
- Pitch circle, Rank-1 temperaments close to specific JI, Temps within ed#, Visualization of isomorphic key mappings, What EDOs have generator sizes/interval ranges, Zeta in Desmos
A full list is on the Xenharmonic Wiki software page.
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