Klein's legs appeared in Lennon and Yoko Ono's 1971 film "Up Your Legs Forever". With George Harrison, Klein co-produced the 1972 concert film "The Concert for Bangladesh". Klein also produced the 1978 film "The Greek Tycoon", in which Anthony Quinn and Jacqueline Bisset played characters based on Aristotle Onassis and Jacqueline Kennedy. In the early 1980s Klein produced two Broadway plays. "It Had to be You", a romantic comedy starring Renée Taylor and Joseph Bologna, ran for barely a month. Next Klein produced "The Man Who Had Three Arms", written by Edward Albee. Although Albee had also written big successes in "The Zoo Story" and "Who's Afraid of Virginia Woolf?", the play Klein produced had an even shorter run than his previous attempt.