Brief Encounter, a musical play adapted by Emma Rice from Noel Coward's film, at the Roundabout Theatre Company. The staging is often magical, taking us in and out of film seemingly at will, as characters disappear into celluloid, the stage becomes a wonder of effects. Much of this is charming, this recreation of the Coward film, opened up with drama, song, and comedy. But more often it is tedious and unconvincing. The leads, attractive and well spoken, and gifted with fine singing voices, are leaden, hardly bringing us into their hearts and minds. The best element of this stew is the singing of classic Coward songs like "A Room With A View." The smaller characters are played with skill, but seem irrelevent, part of what seems like a heavy sales job. When the Warsaw Concerto pounds forth, the uber-Romantic music sounds like a joke. The theater was half-empty and no wonder. Broadway Bridge and Tunnel Test Grade. C.