Franz Schmidt
From the 1950s, Langevin focused on classical music, symphonic music, and writing. Specifically, he wrote articles, monographs and books about Anton Bruckner, Franz Schubert, Guillaume Lekeu, Albéric Magnard, Joseph-Guy Ropartz and Charles Koechlin. He was also interested in works by Hugo Wolf, Gustav Mahler, Arnold Schoenberg, Franz Schmidt, Ferruccio Busoni, Leoš Janáček and Carl Nielsen.