Here is Johnston's entry from the Art Directors Guild Hall of Fame :
A legend in the Variety Show or Musical genre, Johnston won three Emmys® and was nominated an additional ten times. Johnston got his start in art direction with the television series Number Please (1961) and went on to win his Emmys for work on The Mac Davis Show (1974), The Sentry Collection Presents Ben Vereen: His Roots (1978) and Pryor’s Place (1984). In 1978, Johnston received three of the five Emmy nominations for Art Direction of a Variety or Musical Program. He has also worked on iconic series Barbara Mandrell and the Mandrell Sisters, The Flip Wilson Show and The Smothers Brothers Comedy Hour.