When traditional song-and-dance musicals were no longer produced regularly by the studio system, Keel's film career declined somewhat in status and in the volume of his output. He had, however, played in several nonmusical adventure films during his peak, and, after a shot at St. Peter in Frank Borzage's "The Big Fisherman" (1959), moved into action leads for the next decade. His most memorable effort in this phase of his career was the science-fiction flick, "Day of the Triffids" (1962) but he also starred in a handful of minor Westerns including "Waco" (1966) and "Red Tomahawk" (1967). He later performed live, singing in nightclubs, on the Broadway and London stages (in "Ambassador"), and on tour in many musical shows. In 1981, Keel, mustachioed and attractively silver-haired, returned to a wide popular audience for over a decade when he began playing Clayton Farlow, second husband to Miss Ellie (Barbara Bel Geddes) on the popular CBS primetime soap "Dallas".