Hartmann, Arthur - Set of typed letters signed

American violinist (1881-1956), composer and close friend of Claude Debussy. Set of 3 typed letters signed by him, dated in 1917 (2) and 1923 (1), in very good condition. Sizes 7.75 x 10 inches, 8.5 x 6.5 inches, 5.5 x 9 inches.