MacArthur made his Broadway debut in 1960, playing opposite Jane Fonda in Invitation to a March, for which he received a Theatre World Award. Although he never returned to Broadway, he would remain active in theatre throughout his career, appearing in such productions as Under the Yum Yum Tree, The Moon Is Blue, John Loves Mary (with his then-wife Joyce Bulifant), Barefoot in the Park, and Murder at the Howard Johnson's.'Danno' was TV crime-stopper, Barnes, Mike. Hollywood Reporter; Hollywood Vol. 416 (Oct 29-Oct 31, 2010): 8, 87. He also released several records in the early 1960s, scoring two minor hits with "(The Story of) The In-Between Years" and "The Ten Commandments of Love", with the latter peaking at number 94 on the Billboard Hot 100 in 1963.
