He studied the violin with his father (principal viola at the Théâtre de la Monnaie in Brussels and later of the Metropolitan Opera Orchestra), and later with Édouard Deru, Pierre Henrotte and Eugène Ysaÿe. He joined the New York Philharmonic in 1919 as a violinist and was appointed first viola in 1925, a position he retained until 1929, collaborating in those years with Willem Mengelberg, Wilhelm Furtwängler and Arturo Toscanini. It was at Toscanini's encouragement that he began his conducting career.
He studied the violin with his father (principal violist of the Théâtre de la Monnaie in Brussels and later of the Metropolitan Opera Orchestra), and then with Édouard Deru, Pierre Henrotte, and Eugène Ysaÿe. He joined the New York Philharmonic as a violinist in 1919 and was promoted to first viola in 1925, where he collaborated with prominent conductors such as Willem Mengelberg, Wilhelm Furtwängler, and Arturo Toscanini. It was Toscanini's guidance that led him to pursue a career in conducting.