Leonard studied the violin along with his dad, with Rouma, who had studied with Pieltain, Prume, in the Brussels Conservatory, and Habeneck in the Paris Conservatoire. Leonard performed in various and prestigious locations like the Liege Theater, the Theater des Varietes, the Opera-Comique as well as the Academie Royale de Musique. In Paris he could found himself like a virtuoso violinist, and founded the practice of playing chamber music, composing and teaching. Leonard exhibited superb intonation in his playing, an excellent vocal shade in his performing as well as the “sine qua non” of style specifically fitted to chamber music. He advocated the musical compositions of Brahms, Saint-Saens, Faure, Lalo and d’Indy. Sadly, a lot of his music hasn’t survived primarily because of too little unique characteristics. Pedagogically his methodologies had been unparalleled during his period making him among the excellent teachers from the nineteenth century.