The Italian Renaissance composer and theorist Nicola Vicentino (1511–1576) worked with microtonal intervals and built a keyboard with 36 keys to the octave known as the archicembalo. While theoretically an interpretation of ancient Greek tetra-chordal theory, in effect Vicentino presented a circulating system of quarter-comma mean-tone*, maintaining major thirds tuned in just intonation in all keys.

*Quarter-comma mean tone, was the most common mean tone temperament, or tuning, in the sixteenth and seventeenth centuries.