Signed program from the joint performance, New York, 15 May 1977, by the two Broadway legends: the powerful-voiced American actress of stage and film musicals, Ethel Merman, and the beloved American actress and singer, Mary Martin. "Together on Broadway," signed on title-pages. The program, which may be flipped and read from the reverse until mid-point, contains two title-pages, at front and at rear, one listing Merman first, the other listing Martin first (and with commensurate Blackgama "What becomes a Legend most?" fur adverts, featuring each). Merman signed her title-page at upper left, Martin inscribed hers at middle left, in light blue ink: "Love / Mary Martin." Includes patrons list insert. 4to, printed wrappers, stapled. Very fine.