Rock ‘n’ Roll (Bernard B. Jacobs, 242 W. 45). With the end of the stagehands’ strike, Tom Stoppard’s latest play, a study of the last days of Communism in Czechoslovakia and England, has returned to Broadway. Yes, it’s way too long, but that doesn’t make Stoppard’s reflections on philosophical materialism and its emotional discontents any less stimulating or perennially relevant, and Sinead Cusack’s performance in the tricky double role of a mother and her daughter is the stuff Tonys are made of (TT).