The firm of Adrian Le Roy and Robert Ballard in Paris was by far the most prolific publisher of Lasso's music in his lifetime. From 1559 on they included his music in their chanson books, but their first publication devoted entirely to Lasso was the Primus liber concentuum sacrorum of 1564 for five and six voices, followed in 1565 by the Modulorum . . . 4-10 vocum secundum volumen.

Most of the 1564 book was reprinted from Lasso's 1556 and 1562 motet books, but it included three first editions...