Those in search of spiritual enlightenment this weekend will surely find themselves at the Cathedral Choral Society’s “Mystics: Ancient and Modern” concert. If the awe-inspiring acoustics of the gothic structure alone don’t sufficiently humble the soul and meeken the spirit, the dulcet intonations of both the Choral Society and New York’s Ensemble for Early Music will certainly quiet the troubled heart. No program of mystic music would be complete without the inclusion of quintessential mystic composer Hildegard von Bingen’s work, but tonight’s lineup also focuses on the timeless qualities found in this century’s emerging visionary composers: Henryk Gorecki, John Tavener, and Arvo Pärt. A free pre-concert discussion with both ensemble conductors takes place at 2:30 p.m. in the Perry Auditorium, moderated by WETA’s ever-erudite Robert Aubry Davis, and the concert itself begins at 4 p.m. at Washington National Cathedral, Massachusetts & Wisconsin Aves. NW. $15-35. (202) 537-8980. (Amy Domingues)