Two singers were involved, both from the original production. Suzan Hanson was the ghost in the first play, the all-knowing Madam in the second. Herbert Perry (the Leporello in the Peter SellarsDon Giovanni of fabled memory) made the switch from samurai to suited businessman. Both sang with force, but in an acoustical setting that tended to swallow words — a serious problem, since the supertitle projector conked out early in the evening. Robert Israel, stalwart stage designer of the Glass entourage, provided his usual — well, stalwart — set design, consisting mainly, in both plays, of a large, empty box. And “empty” was, indeed, the word.