The majority of pianos today are tuned in Equal Temperament (ET).  This has been the standard way of tuning pianos for approximately  the last 100 years. The piano is tuned in such a way  as to create exact half-steps. All major key signatures have the same key color. All minor key signatures have the same color. Generally speaking (though it may  vary from tuner to tuner), when the modern piano is tuned, it is usually tuned in equal temperament.

Pianos weren’t always tuned in ET.  In the early 20th century and in prior centuries, pianos and other keyboard instruments were tuned in unequal temperaments.  The musicians of those times did not write music using exact half-steps.  Each key signature had its own character.  

A C Major chord  might have soothing harmonies.  A B Major chord might have an edgier harmony.  

Some argue that keyboard music was written in certain keys not only because of fingering, but because the composer wanted a particular key color-its own special harmony and character caused by unevenly spaced half-steps.  A minority go even further and claim that equal temperament was known in prior centuries, but rejected.

Unequal temperaments  give the you the  option of exploring and utilizing other harmonies when playing music.  For example,  if you are playing in equal temperament in the key of C major, then go up, one half-step to the key of C# major to add tension, the key color will remain the same. But, if you do the same thing on a well-tempered piano, a much greater transformation will take place.  A C Major chord will have a sweeter sound in a well tuning than in equal temperament. A C# Major chord will be edgier. The tension is increased even more.

There are piano tuners who believe that it is improper to tune in anything other than equal temperament.  Some view the historical temperaments as a path to developing the ideal: equal temperament.  These old styles are considered obsolete after equal temperament became available.

They have a point. Some of these older temperaments resulted in certain key signatures being unusable because of certain harsh intervals called “wolves.” This limits the player.  

In ET, you can freely modulate between all key signatures.  With some UTs, this is  not possible.  But with the milder UTs, modulation in all keys is not a problem.

When using a 1/4 Comma Meantone Temperament, modulation in all keys is not desirable. There will be a wolf interval at E-flat to G-sharp.

However, when using the 1/10 Comma Meantone Temperament,  the notes vary from Equal Temperament by only a few thousandths of a half-step.  The 1/10 CM is so close to Equal Temperament that a piano tuned that way might technically be considered still to be in Equal Temperament. Modulation in all keys is possible.

Unequal temperaments are used for novelty, the attempt to perform music with historical accuracy, or to alter the resonance of the piano. 

When using UTs that vary widely from ET,  it might even be advisable in some cases to tune A4 slightly lower than 440 Hz to avoid too much stress on certain areas of the bridges and soundboard. 

If you decide to explore unequal temperaments, explore with a piano technician that has some understanding of unequal temperaments.  

Keep in mind that nothing permanent has been done to your piano when it is tuned using an unequal temperament.  If you don’t like the result, just tune it back to equal temperament or try some other UT. 

Both equal temperament and unequal temperaments have their places. String instrument players,  such as guitarists, will routinely use alternative tunings and  there is no controversy.  Why shouldn’t pianists have the same freedom?


Audio Samples:

Equal Substitutes
Just Intonation

Just Intonation

All sequences begin on C

Pythagorean Just Intonation
A = 440
Pythagorean Just Intonation  .ogg
Pythagorean Just Intonation  .mp3

Standard Just Intonation
A = 435
Standard Just Intonation  .ogg
Standard Just Intonation  .mp3


Regular Meantone

Regular Meantone


Christopher Huygens - 31 tones

Gioseffo Zarlino 1558

Gottfried Keller 1707

John Marsh 1809

One-fifth S C Homo. Meantone

One-quarter comma, Aaron

One-sixth Comma Meantone

One-seventh Comma Meantone Romieu

One-ninth Comma Meantone

17/43 Comma Meantone

One-tenth Comma Meantone

Robert Smith - 50 tones

Willaim Hawkes, mercator 1808

Modified Meantone

Modified Meantone

All sequences begin on C

1797 Meantone 1.49627972
A = 439
1797 Meantone 1.49627972  .ogg
1797 Meantone 1.49627972  .mp3

17th Century Meantone Correct
A = 435
17th Century Meantone Correct  .ogg
17th Century Meantone Correct  .mp3

17th Century Meantone
A = 435
17th Century Meantone  .ogg
17th Century Meantone  .mp3

Alexander M. Fisher 1818
A = 435
Alexander M. Fisher 1818  .ogg
Alexander M. Fisher 1818  .mp3

D'Alembert Modified Meantone 1752
A = 435
D'Alembert Modified Meantone 1752  .ogg
D'Alembert Modified Meantone 1752  .mp3

One-seventh Comma Modified Meantone with One Pure Fifth
A = 440
One-seventh Comma Modified Meantone with One Pure Fifth  .ogg
One-seventh Comma Modified Meantone with One Pure Fifth  .mp3

Standard French Rousseau 2 M3
A = 435
Standard French Rousseau 2 M3  .ogg
Standard French Rousseau 2 M3  .mp3

Wendell Synchronous Modern Meantone (Modern)
A = 440
Wendell Synchronous Modern Meantone (Modern)  .ogg
Wendell Synchronous Modern Meantone (Modern)  .mp3

William Hawkes 1798

William Hawkes Improved 1807

Well Temperaments

Well Temperaments


Almost Equal

Aron-Neidhardt 1732

Bailey Equal Beating 2003 (Modern)

Barnes-Bach 1979

Bremmer EBVT 1992 (Modern)

Bremmer EBVT 3 (Modern)

Broadwood Best-Ellis #4 

Broadwood Usual-Ellis #2

Coleman 11 1999 (Modern)

Coleman 16 2001 (Modern)

D'Alembert e-b Well 1752

Early 18th Century Well

George F. Handel 1780

Idealized Prinz etc 0.0

Idealized Prinz etc -3.4

Jean Jousse Well 1832

Kellner Wohltemp-Bach 

Kirnberger Equal Beating 1771

Koval Equal Beating Mini Well (Modern)

Koval Penny Well (Modern)

Koval 0.5 Variable Well (Modern)

Koval 1.15 Variable Well (Modern)

Koval 1.3 Variable Well (Modern)

Koval 1.7 Variable Well (Modern)

Koval 2.0 Variable Well (Modern)

Koval 2.1 Variable Well (Modern)

Koval 2.5 Variable Well (Modern)

Koval 2.9 Variable Well (Modern)

Koval 3.0 Variable Well (Modern)

Moore - Representative Victorian

Peter Prelleur 1731

Preston Equal Beating 1785

Preston Theoretically Correct 1785

Prinz Equal Beating 1808

Prinz Theoretically Correct, etc

Rousseau Equal Beating 1768

Rousseau Theoretically Correct 1768

Secor #2 Well 1975 (Modern)

Stanhope Equal Beating 1806

Stanhope Theoretically Correct 1806

Tuner's Guide #1 Well

Tuner's Guide #2 Well

Tuner's Guide #3 Well

Valotti 1781

Valotti-Young 1799

Wendell Bold Synchronous Well (Modern)

Wendell Natural Synchronous Well (Modern)

Wendell Synchronous Equal Temperament Equivalent (Modern)

Wendell Very Mild Synchronous Well (Modern)

Wendell Well 2002 (Modern)

Werckmeister III 1691

William Tans'ur 1746

Young Representative 18-Century 1799




A. Merrick 1811

Alexander J. Ellis 1875

Alexander J. Ellis 1885

Ellis Tuner #5

Factory Tuners of 1840

Howard Willet Pyle 1906

Jean Jousse 1832

Johann G. C. Graupner 1819

Johann N. Hummel 1829

Mark Wicks 1887

Tuner's Guide Becket

Tuner's Guide Marsh

Viennese (Hummel) 1829


Select Historical

Select Historical


Early French 1650-1710

Pythagorean intonation

Quarter S C  Meantone,  C# - Ab

Quarter S C  Meantone, D#-Bb

Quarter S C Meantone, G#-Eb

Shifted Valotti-Young

Standard French Rousseau 3 M3

Methods Used

Demo Content

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