Efrem Zimbalist Sr. (21 April 1889 – February 22, 1985) was a concert violinist, composer, conductor and director of the Curtis Institute of Music.After graduation he debuted in Berlin (playing the Brahms Concerto) and London in 1907 and in the United States in 1911, with the Symphony Orchestra. In 1912, he played the Glazunov Concerto in a concert marking Leopold Stokowski's first appearance with the London Symphony Orchestra. He then settled in the United States. He did much to popularize the performance of classical music in his adopted country. In 1917, he was elected as an honorary member of Phi Mu Alpha Sinfonia, the national fraternity for men in music, by the fraternity's Alpha Chapter at the New England Conservatory of Music in Boston. He retired as a violinist in 1949, but returned in 1952 to give the first performance of the Violin Concerto by Gian Carlo Menotti, which is dedicated to him. He retired again in 1955. He served as a juror of the International Tchaikovsky Competition in 1962 and 1966.