Over the years LeBow has been one of the most visible and respected actors in the Boston theatre community. Since 1992 Lebow has been a regular at the American Repertory Theatre in Harvard Square, playing plum roles: Marat in “Marat/Sade,” “Full Circle,” which won the Elliot Norton Award, “The Doctor’s Dilemma,” “Shlemiel, the First,” and Steve Martin’s “Picasso at the Lapin Agile.”