Guillaume Costeley was born in Normandy, most likely in Pont/Audemer, in 1530. He occupied the function of organist at the cathedral of Évreux and also became official composer to Charles IX. The status and quality of Costeley’s music warrant his place amongst the principal masters of the Late Renaissance. Although he never abandoned his contrapuntal writing, inherited from his great Franco-Flemish predecessors, his imagination nonetheless led him down paths heretofore little travelled. In spite of being an organist and church musician, it is primarily thanks to his secular oeuvre that he is recognized today, in particular to one piece: the emblematic Mignonne allons voir si la rose, written on a text by Ronsard. Guillaume Costeley composed a large number of 4 and 5part songs, some of which are descriptive (La prise du Havre), serious and moral, others of rustic content occasionally quite risqué (Grosse garce noire et tendre). Our project will draw on this varied repertoire in order to provide a portrait in sound of this great master of vocal music.