The Chicago Chamber Choir, a 40-voice ensemble, concluded its 2018/2019 season with Sergei Rachmaninoff’s All-Night Vigil. Originally intended for liturgical use, these stunning polyphonic settings of Russian Orthodox chant evoke introspection and jubilation in both religious and secular contexts. Rachmaninoff’s orchestration of the choir leads to some of the most awe-inspiring, dramatic moments in choral music.