Randy Kennedy takes a tour of New York theatre intermissions. “The tour, fairly random and thoroughly unscientific, took me from the elegant and easeful (two intermissions, one 40 minutes long, during “Turandot” at the Metropolitan Opera) to the middling (bad red wine and strange fashions in a pretty lounge at the Music Box Theater on West 45th Street) to the merely puzzling (a prominent sign announcing the official Champagne of the Classic Stage Company near Union Square, but no Champagne anywhere in sight). In between, several general rules of intermissions were deduced.”