Born in Roanne in 1879, Léon Vallas studied medicine at the University of Lyon, but abandoned his studies to write a thesis on musicology, La Musique à l’Académie de Lyon au xviiie siècle.
In 1902, he became a music critic for Le Tout Lyon, before founding his own journal La Revue musicale de Lyon in 1903. Close to Georges Martin Witkowski, with whom he had a checkered relationship, he took part in the creation of the Société des grands concerts in 1905, which he did not fail to criticize however.
In 1919 he worked for his PhD on Un siècle de musique et de théâtre à Lyon (1688-1789). He then joined Le Progrès de Lyon where he worked as a music critic for 35 years.
He is the author of biographies of César Franck, Claude Debussy and Vincent d’Indy.
