Say, GorillaMan and pulykamell, I have always been given to understand that Bach had in fact adopted equal temperament and this was the reason for the title of his collection, The Well-Tempered Clavier, in which he explored all twelve keys (which presumably would be difficult without equal temperament).
Have I been misinformed, or is there a subtlety that I’m failing to grasp?
My impression is that Bach wrote The Well-Tempered Clavier for an instrument tuned to “well temperament”, which is different from equal temperament. A comparison of the two can be found here.
MikeS’s link explains this nicely. If I recall correctly, The Well-Tempered Clavier was written to be played in one of the Werckmeister temperaments. A tuning system that is well-tempered is not the same that one that is equal tempered. In an equal tempered system, all twelve keys sound ostesibly the same, as the intervals are the same. In a well-tempered system, all twelve (or most) keys are playable, but each retains its own shade of character, as the relative distances between intervals will vary depending on key. That’s one reason you get quips like “equal temperament is a tuning system in which all keys sound equally bad,” and Mozart’s admonitions against people playing his music in equal temperament.
In the late 1700s and early 1800s, there were whole books on musical theory related to “key color” and explaining the difference of how B minor sounded different than B flat minor, or how C major differed from A flat major. Now, while many musicians today still may refer to things like “key color” and have different psychological associations based on key, when these treatises were written, “key color” was truly a less abstract topic. By that, I mean that in equal temperament C major only differs from A major in terms of pitch. One key is higher than the other, but the ratios between all the intervals remains the same. In a well-tempered system, the keys are playable, but the intervals vary depending on key. For example, in C major, the C-F fourth might be perfect. In A major, the A-D fourth might be a little flat. In E flat major, the Eflat-Aflat fourth might be a little sharp. (I’m just making up these examples; I don’t exactly recall how these notes were tuned with the predominant tuning system of the Classical period.)
Therefore, these keys had an extra element of color that is missing today, and hence Mozart’s (and others) objections.
Please note that this thread is from 2005. While we do allow old threads like this to be raised, we ask that you only do so when you have something new or significant to contribute to the discussion.
Since nothing of substance has been added here, I am going to close this.