Halfway through the Green Mountain Project’s Monday performance of Claudio Monteverdi’s “Vespero della Beata Vergine,” as Jason McStoots and Owen McIntosh virtuosically tripped through the echoing angelic lauds of “Duo seraphim,” Brian Giebler sidled in at mention of the Trinity, and the song coalesced into triadic solidity. It epitomized the music’s palpable architecture. Monteverdi historically straddled a shift in musical thought, from horizontal counterpoint to vertical harmony. One could hear ideas that once would have made Renaissance waves being stacked into pillars and vaults.
The performance of the 1610 Vespers, at St. Cecilia’s Church, was the sixth annual by the Green Mountain Project — an offshoot of Tenet, the New York group founded by soprano Jolle Greenleaf — but hardly rote. Monteverdi left not a fixed work, but a collection of movements to suit various liturgical contingencies.
Music director Scott Metcalfe opted for a larger, more orchestral assemblage, but the ensemble was still compact: 14 instrumentalists and 14 singers, almost never all performing at the same time, the singers almost always one to a part. The intimate forces were leveraged less for speed and agility, and more to tune harmonies and diction to an uncanny degree of precision. Every sound was allowed to establish its presence.
The steady passage of movements (a repeated triptych of chanted antiphon, choral psalm, and smaller-scale sacred song) created a sense of discrete rituals. For all the songs’ similarities to Monteverdian opera — the ballad-like monologue of “Nigra sum,” elegantly sung by Aaron Sheehan; Greenleaf and Molly Quinn making intriguing beauty out of “Pulchra es,” with its disorienting shifts between major and minor — the surrounding formalities made the “Vespers” more a series of tableaux, one self-contained space following another. (The performance made creative use of the space itself: antiphon chants coming from the far end of the altar and the balcony; Sumner Thompson’s orations in “Audi coelum” echoed from the back of the church.)
The final, gently slowing lines of “Ave maris stella” set up a “Magnificat” finale, ever more ruminative, each line with its own setting, instrumentation, and mood. The last “Gloria patri” seemed to occupy multiple rooms, Thompson and Mischa Bouvier singing insistent roulades over the choir’s deliberate serenity. It rose to a powerful conclusion, but Metcalfe tapered off the final “amen,” releasing it into its own reverberation. These Vespers were not so much a point-to-point journey, but a great, grand construction to be inhabited and explored.