[1][4] He was the music director for The Julie Andrews Show and the NBC Follies in addition to serving as arranger and music supervisor for The Gong Show and television specials featuring celebrity entertainers.
[1] In 1962 he was appointed music director of the Los Angeles Civic Light Opera; a post he remained in through 1980.
[1] He produced several film scores during his career, writing music for the movies Deadwood '76 (1965), Guess What We Learned in School Today?
He also composed music for a total of nine Bugs Bunny cartoon specials for television.
In addition to his work as a composer, MacKay also served as music director and/or arranger for several television programs; including The Julie Andrews Show, the NBC Follies, The Gong Show, and television specials starring Carol Channing, Danny Thomas, and Petula Clark.