Technical Library TUNING IX: Cent deviations Entire Contents Copyright © 2011 CBH

Scientists needed some means of describing accurately the differences in pitch, and the cent is defined to be exactly 1/100 of an equal-tempered semitone, ie 1/1200 of an octave.

Cents enable us to compare various temperaments. The following table shows the cent deviations from Equal Temperament for each note of the temperaments already programmed in the now-obsolete Korg MT-1200 tuner:

Notice that a is taken as the reference point—that’s why it’s the same zero in each temperament. Equal temperament is not necessarily the ideal, but it does have the semitones of equal size, so providing a good means of comparison with the other temperaments.

With this data and an electronic tuner of sufficient quality and accuracy, it is possible to check your tuning of different temperaments. Most tuners measure Equal Temperament. As an example, to tune your c in Kirnberger III, the table shows it must be 10 cents sharp compared to Equal Temperament, so instead of regarding the note as in tune when the needle or lights show it to be spot on, you must deliberately tune the c so the needle points to “10” on the sharp side. You must have sufficient resolution in the meter to be able to do this, and the needle mustn’t be dancing around.

Before the popular Korg MT-1200 tuner was rendered obsolete, all our purchasers of this model used to receive a copy of our world-exclusive temperament card which also includes the specifications of another eight often-requested temperaments. We now make this card available to all harpsichord enthusiasts, no matter where they may have bought their original MT-1200.

The later models Korg OT-12 & OT-120 have a slightly different selection of preprogramed temperaments:

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