Garment industry partisans aside, who knew the unrolling of a few yards of imported fabric could be such a palpably sensual, nearly religious experience? Or that unalloyed goodness, usually the deadliest dramatic character quality, could be such an enthralling property in a leading lady? Mostly, fans of Lynn Nottage’s award-winning play, Intimate Apparel, and actress Viola Davis. She plays an African-American seamstress in 1905 Manhattan whose only romantic thrills have been vicarious, through hooker or high-society clients. When this 35-year-old virgin gets courted via mail by an overseas suitor, you almost don’t need the inevitable disappointments of Act 2; the initial glee in her suddenly hopeful, hard-won grin is heartbreak enough. Davis does an unforgettable job of honoring all those women whose souls found song sitting behind a Singer.