New Yorkers devoted to sacred music need no introduction to the choral conductor and organist Kent Tritle, veteran music director of cathedral music at St. John the Divine as well as music director of the venerable professional chorus Musica Sacra. Synergy, you might say, is Tritle’s middle name—as evidenced by the immersive SurRound format he masterminded last year at St. John the Divine, with choristers redeploying in, among, and around the audience according to the character of the music. This year’s all-new SurRound II playlist ranges across a millennium and a half, juxtaposes seventh-century monophonic Gregorian chant with 14th-century polyphony by Pérotin, who blazed new trails of glory at Notre Dame in Paris. Our near-contemporary John Tavener (1944–2013) is heard from too, in the company of Morten Lauridsen, Sarah MacDonald, and Joanna Forbes L’Estrange, all very much among us. —Matthew Gurewitsch