Jean Laurent de Béthizy

Jean Laurent de Béthizy (Dijon, 1702 – Paris, 1781) was a French music theorist and composer whose work belongs to the Enlightenment debate on harmony. He is chiefly remembered today for the Exposition de la théorie et de la pratique de la musique (1754).

As a composer, he premiered the opera L'enlèvement d'Europe at Versailles in 1739, and two of his motets were performed at the Concert Spirituel: Laudate Dominum in 1749, and Domine, Dominus noster in 1756 and 1757. Only two of his small cantatas survive, Le transport amoureux and Le volage fixé, both published in Paris without a date.

As a theorist, he clarified, expanded and revised some of Rameau's ideas and put forward others of his own, such as the concept of 'censée-toniques' and the use of barred figures for dominant chords, which Rameau incorporated into his Code de musique pratique (1760). His polemic with d'Alembert over Rameau's theories, conducted in the Journal oeconomique after the appearance of d'Alembert's Elémens in 1752, left its mark, although in the second edition of 1762 d'Alembert recommended the Exposition as a practical complement.

His identity has been debated. Franceschini linked him with Eugène-Eléonore de Béthisy de Mézières, but the evidence suggests they were different people, and the pamphlet Effets de l'air (1760), sometimes attributed to Béthizy, is in fact the work of Béthisy de Mézières.