Guillaume graduated by Conservatoire de Chambéry. His musical career was started at 2002, when he wrote music for Théâtre d'Icy, played with different jazz musicians, toured Switzerland (with 4tet NOSQUARE). During next years he was busy ,collaborating with many musicians, toured (with 4tet NOSQUARE) Poland, Thailand, Argentina, Chile, Germany, few more times Switzerland, etc. As guest musician participated in several albums. Played concerts with Nguyen Le between others.