Well temperament vs ET

[A440A@aol.com]

Karen Johnson asks;

>If it isn't too much trouble, could someone explain the difference between
>"well" temperament and "equal" temperament?

      Here are some basics,  but Paul B. probably has a more well thought out
description.
P.B.??

Equal Temperament, (ET) is a system of spacing the  12 notes of an octave
equidistant from each other.  The 12th root of 2 is the ratio that forms
between each successive half-step, and all like intervals have the same
amount of tempering.  This means that all fifths sound the same, as do the
thirds.   Modulation in an ET changes the pitch center, and the fingering
pattern on the keyboard, but the interval  relationships remain the same.

    The Well Temperaments did not arrange the notes to meet the mathematical
grid of ET.  The notes are placed so that the dissonance, ( or commas), which
was equally spread around in ET is now placed in varying amounts, depending
on the key signature.  The characteristics of Well Temperament are an
increasing amount of tempering in the root tonic thirds of the keys, as you
ascend or descend in fourths or fifths.   Thirds are never smaller, and
fifths are never wider than  just.  In short, the more accidentals you have
in the key signature, the more tempering you will find in the thirds, and the
less tempering you will hear in the fifths.

Regards,
Ed Foote
Precision Piano Works
Nashville, Tn.