"1984" . . . "37" . "then-AT&T Building" . "535 Madison Avenue" . "550 Madison Avenue" . . . . . "520 Madison Avenue" . . "AT&T skyscraper" . . . "550 Madison Avenue#Sony Building" . . . . . . . "550 Madison Avenue" . . . "AT&T Headquarters" . . . . . . "1983-07-29" . . . "1980" . . . . . . . "AT&T Corporate Headquarters Building (later Sony Plaza, now 550 Madison Avenue)" . . . . . . . "1984" . "197.2056" . "AT&T Building" .