Born on January 23, 2002, Léo Gaillard began his musical education at the Thouars Conservatory at the age of 14. Under the tutelage of his teacher Stéphane Bonneau, he discovered the practice of cello and music. His curiosity led him to explore various musical experiences: contemporary music, local radio, ensemble conducting, music composition, and academic research.

During the 2019-2020 academic year, he decided to pursue his studies at the musicology faculty in Poitiers, earning his bachelor's degree in 2022 and his master's degree in 2024. His master thesis, supervised by Cécile Auzolle, focused on Henri Cuny, an unknown 19th-century composer.

In terms of composition, Léo Gaillard trained under Jean-Louis Agobet at the Bordeaux Conservatory, following the advice of Augustin Braud. During the 2022-2023 academic year, he composed two works. The first, titled Silences, Points et lignes for solo clarinet, premiered on January 23, 2023, performed by Richard Rimbert in Bordeaux. The second, Entraves for female choir and small instrumental ensemble, was commissioned by the Plurielles choir, based in Strasbourg and directed by Mitia Dubois. This piece premiered on September 23, 2023. In May 2024, he obtained his DEM (Diploma of musical studies) from the Bordeaux Conservatory after presenting Pensée Nocturne, Phénomène Polymorphe, and 7 interludes.

For the 2024-2025 academic year, he will work with the Orchestre National de Bordeaux and Jean-Louis Agobet on the creation of his first orchestral piece.