Why does Johann Sebastian Bach’s Mass in B Minor, BWV 232, draw the multitudes? You’d think that music for a solemn liturgy — with a Latin text and extended length — would discourage the public.

On Sunday, J. Reilly Lewis led the Washington Bach Consort in this Olympian work at the capacious National Presbyterian Church in front of a sold-out audience requiring impromptu added seating.

Bach didn’t say how many performers or which instruments were needed for this score, which has been presented by choruses of hundreds but also with a single voice to a part. With a large or small group, the Mass requires superhuman effort to perform. Lewis made it work with a medium-size chamber chorus, an orchestra on period instruments, and vocal and instrumental soloists.

He conveyed all of this music’s complexity with clarity and a sense of wonder. There were powerful implorations for mercy, and sheer elation emerged throughout this colossal score. The ever-fluid, ever-changing motions of Lewis’s hands, especially his fingers, captured all of Bach’s sublime expressions of tragedy, grief or consolation that move human emotions.

Sopranos Agnes Zsigovics and Laura Choi Stuart, countertenor Steven Rickards, tenor Robert Petillo and baritone Jon Bruno, along with superb instrumental soloists, were well-matched and observant of every expressive nuance — not an easy assignment.

Porter is a freelance writer.