How to Make a Guitar Microtonal: Methods, Fret Placement and Setup

A standard guitar divides the octave into twelve equal semitones. A microtonal guitar adds access to pitches between—or outside—those fret positions, making it possible to explore makam and maqam intonation, just intonation, alternative equal temperaments and contemporary microtonal composition. You can modify an existing guitar, but the best method depends on whether you need a temporary experiment, a repeatable stage instrument or a permanent custom system.

Important: do not cut the fingerboard, pull frets, drill holes or apply permanent adhesive unless you understand the effect on scale geometry, action and resale value. Irreversible work should be planned and carried out by an experienced guitar technician or luthier.

What Makes a Guitar Microtonal?

“Microtonal” does not describe one universal tuning. It can mean pitches required by a specific makam or maqam, intervals derived from whole-number ratios, an equal division such as 19-, 24- or 31-tone equal temperament, or a composer’s custom pitch set. Decide on the musical system before placing any additional fret.

The adjustable microtonal guitar developed by guitarist and academic Tolgahan Çoğulu uses small movable fret pieces under individual strings. This approach allows different layouts without permanently filling the fingerboard with full-width frets. It is one important design among several, not the only form of microtonal guitar.

Related: All About the Microtonal Guitar.

Five Ways to Add Microtonal Pitches

Choose a Pitch System First

Makam and maqam practice

Turkish makam and Arabic maqam are not reducible to one fixed “quarter-tone” grid. Pitch placement can depend on tradition, seyir or melodic context, performer, ensemble and expressive intonation. Work from a teacher’s specific pitch targets or a documented system rather than placing every note exactly halfway between standard frets.

Equal temperaments

Systems such as 19-TET, 24-TET and 31-TET divide the octave into equal steps. Each requires its own fret positions. A 24-TET quarter-tone layout is useful for some music and experiments, but it is not a complete model of every makam or maqam tradition.

Just intonation and custom scales

Intervals defined by frequency ratios require positions calculated from those ratios. A composer may also choose a small collection of extra pitches rather than a full system across the neck.

How Fret Position Is Calculated

For an equal division of the octave into N parts, the distance from the nut to step n is:

d = L × (1 − 2^−n/N)

Here L is the guitar’s actual scale length. For a ratio-based interval with frequency ratio r, the distance is d = L × (1 − 1/r). These are theoretical starting points. Nut height, string gauge, action, stiffness, playing pressure and compensation alter the sounding result, so final placement must be checked with a reliable tuner and the intended technique.

Reversible Method: Movable Fretlets

1. Define the pitches. Write down the exact cents, ratios or reference notes needed.
2. Measure the real scale length. Measure from the nut’s witness point to the bridge saddle contact point; individual electric-guitar saddles may differ.
3. Calculate initial positions. Mark with low-tack removable tape, never by cutting first.
4. Prepare the surface. Follow the fretlet maker’s instructions and test any attachment material in an inconspicuous place.
5. Install one pitch at a time. Ensure the fretlet sits under the intended string, has enough height to speak and does not interfere with neighbouring strings.
6. Verify from both directions. Approach the pitch melodically from below and above, then test it in the actual phrase and register.
7. Recheck after playing. Confirm that nothing shifted and that adhesive has not affected the finish.

Use only a purpose-designed removable system suitable for the fingerboard finish. Household glue, metal strips with sharp edges and improvised screws can damage the instrument or the player.

Permanent Refretting and Added Frets

A permanent conversion can be more stable for touring and repeatable repertoire, but accuracy is unforgiving. The technician must plan fret slot locations, fret height, crown, levelling, neck relief, nut and bridge setup, and possible conflicts where partial frets cross adjacent strings.

• Choose a dedicated layout before any slot is cut.
• Provide the luthier with cents, ratios or exact tuning documentation—not only note names.
• Decide whether every string needs the same extra pitch.
• Plan visual markers so the player can navigate the denser fingerboard.
• Expect a complete setup after fret work.

Removing standard frets to make the guitar fretless is also permanent in practical terms. Filled slots, fingerboard levelling, nut adjustment and a suitable playing surface may be required.

Setup, Strings and Intonation

Extra frets do not automatically make the instrument play in tune. Very low action may cause new fretlets to buzz or fail to sound; very high action can sharpen notes when pressed. Different string gauges and materials change stiffness and compensation. Check open strings, standard frets and new pitches after every material change.

For electric guitar, test clean before using distortion or modulation, because effects can hide buzzing and pitch instability. Chords also reveal errors that a single melodic line may conceal.

How to Practise Microtonal Guitar

• Learn the sound of each added pitch before memorising a new shape.
• Practise slow drones and short melodic phrases rather than only chromatic exercises.
• Compare the added pitch with its melodic function, not merely a tuner display.
• Use bends and slides intentionally; they remain expressive tools, not substitutes for stable target positions.
• Record yourself with accompaniment to hear whether intonation works in context.

A fretless guitar offers continuous pitch control, while a fretted microtonal system offers repeatable landmarks. Neither is automatically more authentic; the right choice depends on musical language and technique.

Common Mistakes

Frequently Asked Questions

Can any guitar become microtonal?

Most guitars can access microtones through bends, slides, a removable system or digital processing. A physical fret conversion depends on fingerboard geometry, action, finish and intended layout.

Do I need to remove the existing frets?

No. Movable or additional partial frets can preserve the standard twelve-tone layout. Removing frets is relevant only when you specifically want continuous fretless control.

Is a quarter-tone guitar suitable for Turkish makam?

It can be useful, but equal quarter-tones do not reproduce every pitch or expressive practice in Turkish makam. Follow a teacher and the intonation of the chosen repertoire.

Can I install fretlets myself?

A well-designed removable kit may be installed by a careful player following its instructions. Permanent slots, fret removal or finish-sensitive adhesive work should go to a qualified technician.

Explore available microtonal guitar fretlets, or contact Sala Muzik to discuss compatibility before ordering.