In 1570 Le Jeune began his association with the "Academie de musique et de poésie", headed by Jean-Antoine de Baïf, an association which was to be decisive both on Le Jeune's music and on the direction taken by the Academie. That Baïf was a Catholic, who even wrote a sonnet extravagantly praising the St. Bartholomew's Day Massacre in 1572 (in which somewhere between 5,000 and 30,000 Protestants were murdered) appears not to have dissuaded Le Jeune from working with him, and Le Jeune continued to set his poetry, and follow the ideals of the Academie, into the 1580s. In 1581, in collaboration with Baïf, d'Aubigné and Ronsard, he wrote incidental music for the wedding of the Duke of Joyeuse and the queen's half-sister, Marie de Lorraine.