Orthodox priests in black robes and conical caps rubbed shoulders with pop stars and actors, including Björk, Antony Hegarty and Keanu Reeves, at Carnegie Hall on Saturday at a sold-out concert of music by Arvo Pärt. No other living composer has so fervent a following or such a diverse group of fans. When Mr. Pärt, bearded, frail and smiling shyly, took a bow at the end of the evening — this was his first visit to New York in 30 years — the roar that greeted him seemed unanimous.

Estonian Philharmonic Chamber Choir Robust sound and plaintive whispers: The choir performing Arvo Pärt’s “Kanon Pokajanen” on Monday evening in the Temple of Dendur at the Metropolitan Museum of Art.

Music Review: Arvo Pärt’s ‘Kanon Pokajanen,’ at the MetJUNE 3, 2014
What is it about Mr. Pärt’s quiet, austere compositions that stirs such passions? It’s a question at the heart of the Arvo Pärt Project at St. Vladimir’s Orthodox Theological Seminary in Yonkers, which painstakingly prepared a current series of concerts devoted to the composer and panel discussions on the Eastern Orthodox spiritual traditions that feed his music. The focus of Saturday’s concert was the sacred choral works with which this Estonian composer, now 78, has affirmed that faith in recent years. But a meditative quality suffuses even his purely instrumental works.

The evening opened with two early examples of these from “Tabula Rasa,” the 1984 ECM recording that brought Mr. Pärt international fame: the lightly pulsating “Fratres,” in a version for violin, string orchestra and percussion, with Harry Traksmann ably performing the solo part, and the elegiac “Cantus in Memory of Benjamin Britten.” The Tallinn Chamber Orchestra, conducted with authority and grace by Tonu Kaljuste, brought out the clarity of the harmonic progressions in these deceptively simple pieces, as well as the gradual buildup of sonic texture and emotional weight that makes them so riveting.

The first-rate Estonian Philharmonic Chamber Choir joined the orchestra for the remainder of the program. Their performance of “Adam’s Lament” was emotionally devastating, traversing expressions of grief, bitter anger and hope. In “Salve Regina,” a celesta joined the choir and string orchestra, adding a touch of radiance to what is otherwise a private, almost reticent affirmation of faith.

For the Te Deum, the choir divided into three spatially separated groups, and a wind harp and a piano lent atmospheric touches to the orchestration. Mr. Pärt’s setting of the liturgy is strikingly different from the brilliant Te Deums of previous centuries, in which the glorification of God is confidently expected to reflect back on the performer and patron. Here, reverence is expressed as a gentle, devotional ritual, its methodically layered harmonies resembling the act of applying tiny flakes of gold leaf to a Madonna.