String Inharmonicity on an Electric Guitar

This Harmonic Tuner Intonation Expert app measurement shows, how inharmonicity varies from string to string and increases on upper frets of a Fender-scaled electric guitar (0.010-0.046 strings).

Inharmonicity on plucked or hammered strings is a consequence of string stiffness an leads to widened intervals between a note’s harmonics – compared to the perfect intervals formed by theoretically exact harmonic overtone series (as achieved by bowed strings or blown instruments). Harmonic Tuner’s metric of inharmonicity is Cent per harmonic (c/h) and expresses, by how many cent harmonics are tuned too high compared to the next lower harmonics. See Harmonic Tuner’s special bargraph view of harmonic’s individual tuning below – the example shows the note A (440 Hz) played on a stringed instrument resulting in a significant inharmonicity metric of 4.3 c/h.

To make intervals sound consonant on instruments with hammered/plucked strings like pianos, stretch tunings are applied. They widen intervals between fundamental frequencies to get a better match of harmonic’s frequencies. Harmonic Tuner Intonation Expert allows for widening tunings in the range of 0 to 5 cent per octave. Use the inharmonicity protocol as shown above to quickly measure, what’s the inharmonicity of your instrument’s strings and find a matching stretch value.

See the Harmonic Tuner Guitar Setup example video clip to see how to combine inharmonicity measurement with stretch tuning and intonation setup in Harmonic Tuner Intonation Expert to get an optimal guitar setup.

Optimal intonation with Harmonic Tuner Guitar Setup for Android

Demo clip of the new Harmonic Tuner Guitar Setup & Harmonic Tuner Intonation Expert apps for Android.

Video sections:

  • 0:00 Check nut / bridge adjustment of a guitar (Example: bad intonated guitar)
  • 0:48 Check nut adjustment for all strings of an electric guitar (Strat type)
  • 2:11 Check bridge adjustment (some strings on a Strat type guitar again)
  • 5:07 Measure string inharmonicity for intonating an electric guitar in proper stretched tuning (Les Paul type guitar, Intonation Expert app)
  • 6:49 Check intonation error at the bridge (using the stretch tuning, LP guitar)
  • 7:28 Re-check intonation with the now corrected bridge intonation (LP guitar)

Get Grain Apps on Google Play.

Update 1.14 of Harmonic Tuner app family now on Google Play

Sustain Analyzer and Guitar Setup: new features in the first common update of the Harmonic Tuner apps as a family of 7. Visit Grain Apps on Google Play.

The new instrument bridge/nut adjustment features of Harmonic Tuner Guitar Setup app are now also a part of the most versatile tuning tool Harmonic Tuner Intonation Expert. Use it here with stretch tunings (suiting your guitar’s inharmonicity, easily measured with Intonation Expert) or use it to adjust intonation even of unusually fretted instruments of unequal temperaments.

Sustain Analyzer now has some new useful features:

  • Compare several stored sustain measurement protocols directly
  • Display the initial levels of the measured harmonics at note attack (as additional bar diagrams or intuitively as brightness of the sustain bargraphs)
  • Configurable unit of sustain (Seconds or dB/s)
  • New curve-style protocol look
  • Improved sustain / decay measurement for more accuracy

Example: Similar dead spots of first harmonic (fundamental) on two “Tele”-style electric guitars (new curve-type plot):

The same dead-spot measurement data in the conventional dot-style diagram.

Initial levels of harmonics displayed in the sustain bargraph module if activated in app settings – now displaying decay time T60 in seconds.


NEW on Google Play: Harmonic Tuner Guitar Setup

Easily set up guitar & bass intonation: Detect bridge and nut errors & adjustments with Harmonic Tuner Guitar Setup.

Harmonic Tuner Guitar Setup is a novel tuner app for easy and quick intonation assessment & setup of fretted instruments like guitar, bass, mandolin, ukulele etc. Only a well-intonated instrument sounds perfectly in tune along the whole fretboard.
The app shows how much bridge and nut of a guitar should be adjusted to get optimal intonation on your instrument based on only a few automated tuning measurements of your string’s notes. If string length is too short or too long at bridge or nut, the errors are shown as millimeter or inch values.
Use the app to perfectly set up your own instrument or to compare instruments in the shop, checking if the nontrivial task of nut adjustment was properly done by the luthier / manufacturer.

Get Harmonic Tuner Guitar Setup on Google Play.

The protocol diagram shows the tuning difference of fretted notes to the open string. Use the Zoom Button and Intonation Table for a detailed view. Adjustment of bridge and nut is usually only needed if average tuning deviation exceeds a 1 cent tolerance significantly.

Harmonic Tuner Guitar Setup eases the precise intonation assessment and correction of guitar setups. Compared to the conventional intonation setup method, this app does not require the string being precisely tuned +/-1 Cent to reference, because only the tuning difference is relevant here. Harmonic Tuner has the advantage of evaluating multiple notes to calculate a more precise adjustment error. Furthermore the amount of error is displayed, so time-consuming trial-and-error adjustments can be skipped.

More tuning protocol features (storing, comparing protocols, …) are available in Harmonic Tuner Intonation Expert. The upcoming next version of Intonation Expert will have the new Guitar Setup features as well, supporting even stretch tuning adjustments and adjustments for special unequal temperament fret/nut layouts.

See how significant the degrading effect of  worn strings on intonation and adjustability is: Worn vs. fresh strings, measured with Intonation Expert for Android.

Fine-tune a Hohner Melodica using Intonation Expert app

Tuning protocols of a Hohner Melodica “student 32” Before & after fine-tuning the intonation by filing the instrument’s metal reeds. Quickly create tuning protocols using Harmonic Tuner Intonation Expert app for Android and detect notes that need tuning.

Directly compare both protocols using the protocol overlay feature of Intonation Expert:

Video demo: Get tuning protocols of your instrument using Intonation Expert

Worn vs. fresh guitar strings

Compare string sets with Harmonic Tuner Intonation Expert for Android – Worn (left) vs. fresh (right) guitar strings – strong effect on intonation, tuning and adjustability

The two tuning protocols show the high E string (0.010″) of an electric guitar and the tuning at each fret. The worn string (left) leads to significantly lowered notes at middle frets an too high notes at higher frets, this string can not be set up for proper intonation. The fresh string on the same guitar and bridge setup gives nearly perfect intonation.

Intonation Expert – Temperament Detector

Intonation Expert offers a tool to recognize typical temperaments mainly from polyphonic solo keyboard performances / recordings. Like the Reference Pitch detector, the Temperament Detector performs a long time analysis of the audio signal. Tuning Spectrums for each note are displayed in a Temperament Spectrum diagram and compared with the internal Temperament database to get a best-fit Temperament suggestion.

Youtube Demo Clip (Example: Detection of Tuning Temperaments from polyphonic organ music)

A piece played at Werckmeister tuning at A=442 Hz while it is analyzed in Temperament Editor:

Intonation Expert – Temperament Editor & Analyzer

Inspect the factory temperament presets, modify them or enter / create your own temperament presets with Temperament editor.
Temperaments can be compared with a useful diagram overlay function.
The harmonic consonance/dissonance behaviour of a temperament’s chords is displayed as deviation from perfect intervals (fifth, thirds).
Use your reference instrument measurement created with Intonation Protocol to fine and store as a preset with Temperament editor.
Find similar temperaments to the temperament you are editing using Temperament Editor’s statistics/comparison functions.

Youtube Demo Clip (Example: Creating a custom temperament preset from an intonation protocol measurement, German language)

Built-in Werckmeister temperament scale shown in Temperament Editor:

Built-in Vallotti temperament compared to another temperament shown in overlay background:

List of temperaments most similar to currently edited temperament presets and their best-fit root transpositions:

Deviation of all fifths and thirds within the equal temperament from the perfect intervals:


Deviation of all fifths and thirds within the Meantone 1/5 temperament from the perfect intervals, as activated in the overlay menu:

Built-in Pythagorean tuning temperament and its characteristic deviation of fifths and thirds from perfect intervals:

Intonation Expert – Stretch Tunings and Unequal Temperaments

Stretch tunings are common on pianos: instruments with plucked or hammered strings show slightly inharmonic overtones. Harmonic Tuner allows to widen octaves by 0 to 5 cent accordingly. Use the Inharmonicity protocol module to check the inharmonicity range of your strings, than set the stretch tuning accordingly.
Historical keyboard music on organs, harpsichords etc. is typically performed using historic temperaments that provide individual consonance/dissonance characteristics for each key/scale. Harmonic Tuner Intonation Expert supports a set of popular historic temperaments you can tune your instrument to. The root note of each temperament scale can be transposed. The amount of the temperament can be scaled from 5% to 100%

Built-in Temperaments

Youtube Demo Clip (Example: measure tuning/inharmonicity protocols of historically tempered and and stretch tuned keyboards, adjust tuner accordingly)

Youtube Demo Clip (Example: measure and compare different piano simulations on a digital piano regarding tuning and stretch, work with protocol overlays)

Setting up the tuning reference (example: unequal stretch tuning at baroque concert pitch of 415 Hz):

Protocolled sequence of tuning measurements and detected Kirnberger III temperament:

Quick-select of tuner temperament via menu:

Intonation Expert – Tuning & Inharmonicity protocols

For precise assessment of an instrument’s intonation, stretch tuning, temperament etc., tuning/inharmonicity of a whole series of notes is recorded and displayed in a diagram. When measuring keyboard with historic tunings, a Temperament detection recognizes the best-fitting out of a number of popular historic temperaments.
The intonation protocols are useful for checking and setting up guitar/bass intonation, for measuring pipe organs or to measure the intonation and tuning stretch of an instrument. Sets of measurements can be compared and stored. The raw protocol data can be exported as a table via text clipboard.

Youtube Demo Clip (Example: measure and compare different piano simulations on a digital piano regarding tuning and stretch, work with protocol overlays)

Youtube Demo Clip (Example: Guitar and Bass setup)

Tuning curve of a digital piano’s Rhodes simulation:


Tuning curves of different digital pianos compared using Overlay functions:

Intonation of the six strings of an acoustic guitar that needs a setup:

Inharmonicity protocol of a digital piano:

Inharmonicity protocols of a digital piano and a Rhodes simulation:

Data table of the measured protocols:

Harmonic Tuner Intonation Expert – Built-in Temperaments

Equal, Werckmeister III, Kirnberger III, Neidhardt I, Sorge, Freiberg (Silbermann), Rameau, Vallotti, Pythagorean, Meantone 1/3, Meantone 2/7, Meantone 1/4, Meantone 1/5, Meantone Silbermann, Meantone 1/6, Just
(Additional custom temperaments can be created, edited and stored)

Temperaments relative to equal chromatic scale (cent):

Temperaments as fractions of Pythagorean (PC) or Syntonic (SC) Commas, modifying circle of perfect fifths: