Well-tempered

What it means

A tuning is called well-tempered when all twelve keys are usable, without all sounding the same. It distributes the unavoidable difference between pure intervals — the comma — unevenly across the fifths, so that frequently used keys sound purer and remote ones, though rougher, stay playable. In this it differs from two other solutions.

Musical use

Meantone temperament, widespread in the Renaissance and early Baroque, narrows the fifths strongly, in order to gain as many pure major thirds as possible. The result sounds extraordinarily pleasing in the common keys but makes remote keys unusable — there the so-called wolf fifth arises.

Equal temperament, generally usual today, distributes the difference evenly across all twelve fifths. Every fifth is slightly too narrow, every major third noticeably too wide, but in return all keys sound the same and any modulation is possible. The price is that no key retains a character of its own.

Well temperaments lie between these and were in use in the eighteenth century in several variants. They make playing in all keys possible while retaining their different characters at the same time — a circumstance that explains the widespread talk of the character of keys. “Well-tempered” and “equal-tempered” do not mean the same thing; the equation is widespread but incorrect.

In the seventeenth and eighteenth. The keys retain different colourings in the process. Bach's Well-Tempered Clavier uses all 24 keys but prescribes no particular tuning; whether equal or unequal temperament was intended is disputed.

Performance practice

If you play a harpsichord or an organ in a historical tuning, work out beforehand which keys sound pure and which rough — the choice of pieces is guided by this. In an ensemble without a keyboard instrument, intonate freely by the beats, even if this deviates from the piano. And when listening to recordings of older music, listen deliberately for the difference; it explains a good deal of what otherwise sounds like impurity.