In 1937, Wagner joined the MGM chorus in Hollywood and was subsequently appointed Music Director of St. Joseph's Church in Los Angeles where he established an outstanding choir of men and boys, including a young Paul Salamunovich. In 1945, Roger Wagner became the supervisor of young choruses for the City of Los Angeles, most notably the "Los Angeles Concert Youth Chorus." It was from a madrigal group of twelve of these singers that the soon world-renowned Roger Wagner Chorale was born in 1946.