Arnold Schwarzenegger joins an improv troupe. Arnold Schwarzenegger joins an improv troupe, to partake in some low-profile, low-pressure acting. On his first night on board, the first scenario is a meeting of famous classical composers from throughout history. ""Let's plan our roles before we go on stage,"" says the troupe leader. ""I'll be Mozart."" ""I'll be Vivaldi,"" says a member. ""I'll be Handel,"" says another. ""What about you, Mr. Schwarzenegger?"" says the leader slyly. ""What role wo…