American avant-garde composer, pianist, author, and inventor (1900-1959) who co-patented a 'Secret Communications System' with actress Hedy Lamarr in 1941. AMQS on an off-white 5 x 3 card imprinted "Collection of Bernard J. Klug." Antheil pens two bars from one of his works, signing below in bold ink, "October w9, 1954, George Antheil." In fine condition. Encapsulated in a PSA/DNA authentication holder.