Autograph signature from the legendary Boston Symphony conductor, signed on an index card, together with two photographs of Koussevitzky broadcasting at an NBC microphone, ca. 1930's. Signature 5 x 3 inches (12.7 x 7.6 cm), photographs 8 x 10 inches (20.3 x 25.5 cm). Small edge tear to one of the photographs; overall fine.