Lemme Rossi (died 1673) was an Italianmusic theorist who was the first to publish a discussion of 31 equal temperament, the division of the octave into 31 equal parts, in his Sistema musico, ouero Musica speculativa doue SI spiegano i più celebri sistemi di tutti i tre generi of 1666. This slightly predates the publication of the same idea by the eminent scientist Christiaan Huyghens. Events January 22 - Impostor Mary Carleton is hanged in Newgate prison in England for multiple thefts and returning from penal transportation March 18 - John Berkeley, 1st Baron Berkeley of Stratton sells his part of New Jersey to the Quakers. ... Music theory is a field of study that investigates the nature or mechanics of music. ... In music, 31 equal temperament, called 31-tet, 31-edo, or 31-et, is the scale derived by dividing the octave into 31 equally large steps. ... In music, an octave (sometimes abbreviated 8ve or 8va) is the interval between one musical note and another with half or double the frequency. ... Christiaan Huygens Christiaan Huygens (pronounced in English (IPA): ; in Dutch: ) (April 14, 1629âJuly 8, 1695), was a Dutch mathematician and physicist; born in The Hague as the son of Constantijn Huygens. ...