Leroy attended high school at Lycée Claude Monet, where he studied under composer Annick Chartreux and performed in numerous concerts as a pianist and singer.

After having written various chamber pieces in his teens (his minimalist duology, 2017, was premiered at the Conservatoire Municipal de Paris Maurice Ravel and at Lycée Claude Monet in 1999), he applied in 2001 for the Berklee College of Music in Boston, for which he was awarded a scholarship.

At Berklee, where Leroy studied Film Scoring,[1] he founded the school's first student-run classical orchestra,[2] which produced its first recording in April 2004 and a string of concerts in the following years.

[3] After graduating from Berklee College of Music in the Spring of 2005, Leroy moved to Los Angeles to pursue a career in the film and TV industry, where he first started working as a technician and assistant for various composers.

Around the same period, he also re-orchestrated a suite from Basil Poledouris's score to Conan The Barbarian, to be performed under the composer's direction in July 2006, at the second International Film Music Conference in Úbeda, Spain.