Born in Normandy, France, Guillaume moved to Paris in 2001 to attend the American School of Modern music where he studied guitar, improvisation, harmony, composition, orchestration and more.
After receiving the Pierre Aguiton award and a scholarship from Berklee College of Music, Guillaume moved to Boston where he gratuated "Summa cum laude" from Berklee in 2009. In Boston, Guillaume had the opportunity to learn with some of the best teachers in the US (Mick Goodrick, Tim Miller, David Gilmore to name a few).
Since then, Mr Estace has been touring and teaching in Europe, United-States, Canada, Japan, Ukraine, UK, he toured with Vanessa Paradis, Matthieu Chedid, Ayo, Jane Birkin, Angelo Debarre, Stan Harrison, Gary Georgett and Lulu Gainsbourg in 2011-2013 for the Serge Gainsbourg tribute "From Gainsbourg to Lulu". Active on the jazz scene, he also plays in Lulu Gainsbourg's band since 2014 to promote the album "Lady luck" with Brad Thomas Ackley and Lawrence Clais.