An unequal temperament is described in which the fifths and fourths of the tuning chain have the same beat rate. No Wolf intervals are produced and all intervals can be described by ratios of integers. The equal heating chromatic scale is an excellent approximation to equal temperament; moreover it may well represent a closer approximation to Bach's “well-tempered tuning” than does equal temperament. Circulation of a kind is complete and this tends to restore in some degree the feature of key color. Inasmuch as there is only one beat rate to observe (very nearly one per second) the procedure for tuning keyboard instruments to this temperament is simpler than that nominally required for equal temperament. Tuning notes are appended.