In the Conservatoire National de Région de Paris, he studied conducting with Dominique Rouits. From 2001 to 2003, he was composer in residence at the Orchestre National des Pays de la Loire, for which he wrote the vocal symphony Liturgies de lombre, from 2009 he has been composer in residence at the Orchestre de Pau, Pays de Béarn. Connesson teaches orchestration at the Conservatoire National dAubervilliers-la Courneuve, guillaume Connessons music is published by Éditions Billaudot