Donald Nally conducts the Cathedral Choral Society on Sunday, with Thomas Mesa on the cello, at Washington National Cathedral. (Mauricio Castro /Mauricio Castro )

The Cathedral Choral Society announced last fall that Steven Fox would be its new music director, starting with the 2018-2019 season. Guest conductors have been carrying the ensemble along since it lost its beloved music director, J. Reilly Lewis, almost two years ago. On Sunday, Donald Nally, conductor of the Crossing chamber choir, led a meditative program of music at Washington National Cathedral.

Nally’s program was built around an esoteric quotation from French writer Pascal Quignard, but it added up to two hours of predominantly slow-moving, reflective music. Nally elicited a focused, often soft sound from the volunteer choir of about 150 people, well blended even though they were seated in sections. The amorphous textures and slow textural shifts of pieces such as the “Sanctus” movement from Sebastian Currier’s “Night Mass” worked well in the cavernous space, where sound takes a long time to decay.

Intonation issues crept up, especially with the tenors and sopranos, meaning that in some unaccompanied works, organist Scott Dettra’s shadowing was needed to keep the choir on pitch. The most successful pieces were those designed for this kind of venue and ensemble, especially Herbert Howells’s coronation anthem “Behold, O God our defender.” Dettra, formerly the cathedral’s principal organist, accompanied with a diverting range of registrations.

Cellist Thomas Mesa ably accompanied several of the pieces, having his own solo turn in “Gramata Cellam” by Peteris Vasks. The concert’s most striking moment came in this piece’s second movement, when Mesa accompanied his own voice for a haunting, wordless melody.

Nally included two world premieres in the program. A simple setting of a childlike Christina Rossetti poem by Eriks Esenvalds, “85” was saccharine in harmonic content. Nally commissioned Alex Berko’s “Lincoln” directly in response to the immigration controversies of the past year. Half-sung, half-spoken, it was more difficult to put together, but Nally led with a sure hand.