Charles KOECHLIN (1867-1950). L.A.S., Thursday afternoon [January 16, 1939, to violinist Yvonne Astruc]; 2pages oblong in-8. He thanks her for her "beautiful interpretation of my Sonata! [...] On Radio it sounded very good - except that the sound engineers attenuated the piano too much". He has just heard on Belgian Radio "Darius Milhaud's 1st Symphony, so moving and with some pages of great beauty. What a joy to reconnect with his music!" Enclosed is a double typed letter from Yvonne Astruc to Koechlin, January 18, 1939, announcing that she will be playing her Sonata at Radio-Paris with Jean Doyen.