revised by Charles Corey
Systems of organization of the pitch scale. Such systems are either “just” or “tempered.” Just systems consist entirely of pure intervals, and though literal transposition of patterns or scales may be very limited, other musically useful symmetries are available. Tempered systems are those in which the purity of some or all intervals is deliberately compromised in order to render other intervals less impure, and thus increase the number of musically serviceable intervals. Over the course of centuries countless tunings and temperaments have been proposed, but few have been of practical importance; of these, 12-tone equal temperament has become the standard in Western music since the 19th century.
Until about 1850 many organs in New England were tuned to some practical variant of meantone temperament, while in areas of German influence (such as the Moravian communities) equal temperament prevailed. The universal acceptance of 12-tone equal temperament as standard from the mid-19th century nearly silenced discussion of alternative systems; only a few isolated composers and theorists advocated or experimented with non-standard tuning systems before about ...