Sébastien de Brossard (ca. 1655–1730) was a French composer, music theorist, and musicologist, primarily associated with the early Baroque period. He is best known for his contributions to sacred music and his pioneering work in music theory. De Brossard's genre primarily encompasses choral and instrumental music, with a strong emphasis on liturgical compositions. Notable works include his collection of motets and the "Dictionnaire de musique," published in 1703, which was one of the earliest music dictionaries and played a significant role in the dissemination of music theory during his time. His works often reflected the evolving styles of the Baroque era, incorporating elements of both French and Italian music traditions. De Brossard's impact on music lies not only in his compositions but also in his efforts to codify and document music theory, influencing future generations of musicians and theorists. His commitment to the development of musical education and understanding helped lay the groundwork for more systematic approaches to musicology and theory in the 18th century. Through his writings and compositions, he significantly contributed to the cultural landscape of his time and the evolution of French music.