Stepping into entertainment, he made his debut in 1962 as a singer with Mitch Miller’s PG-rated ensemble. Miller had a hit TV series and string of records under the “Sing Along With Mitch” banner that featured wholesome singers delivering pop standards. McGrath also appeared with Miller’s ensemble for a residency at Las Vegas’ Desert Inn during the summer of 1964. At a time when Beatlemania was sweeping the nation, McGrath was delivering “Danny Boy” and “On the Street Where You Live” in a Vegas showroom.
By the mid-1960s, McGrath was actively pursuing his solo recording career as well as acting. In 1966 he signed with Columbia Records’ Japanese label, Nippon Columbia. For a time, McGrath performed regularly in Japan.