Dumage’s first music teacher was probably his father, the organist of the Beauvais Cathedral. At some point during his youth Dumage moved to Paris and studied under Louis Marchand. He also befriended Nicolas Lebègue who, in 1703, procured for him the position of organist of the Saint-Quentin collegiate church. In 1710 Dumage was appointed titular organist of the Laon Cathedral. Due to strained relations with his superiors in the cathedral chapter, Dumage left on 30th March 1719, at the age of forty-five, and became a civil servant. He apparently neither played nor composed music professionally until his death, thirty-two years later.
Dumage’s only surviving work is the Premier livre d’orgue, published in 1708. This collection is dedicated to the chapter of Saint Quentin. It contains a single “Suite du premier ton”: eight pieces in the traditional French forms: Plein jeu, Fugue, Trio, Tierce en taille, Basse de trompette, Récit, Duo, and Grand jeu. In the brief preface Dumage explains that these are his first works, and that he modelled himself on the music of his former teacher Marchand. Dumage’s music is, however, of very high quality, and entirely representative of French organ music of the period. Dumage’s Second livre d’orgue was presented in 1712 to the chapter of Laon Cathedral, but has never been found.