Music Before 1800

This afternoon's performance, a concert account of Marc-Antoine Charpentier's Acteon featuring period-instrument ensemble Juilliard415 with vocalists from the school, is nearly sold out, presumably thanks in part to conductor and early-music magus William Christie—only seats without a view remain. But given that Christie has canceled nearly all of his recent performances while recovering from surgery, it remains to be seen just who will turn up on the podium here.