CAMBRIDGE — How long should an ensemble be called "young"? The ensemble in question is Stile Antico, the British vocal ensemble founded in 2001. However short its lifespan in comparison with similar groups — the Tallis Scholars, for example — there is nothing underdeveloped about its collective talent or the distinctiveness of its approach. By now, "authoritative" is probably a more accurate label, regardless of how long Stile Antico has been in the game.
For its latest appearance in the Boston Early Music Festival series, the group brought most of its latest recording. "From the Imperial Court" samples 15th- and 16th-century works composed for the Hapsburgs, the political dynasty that ruled various parts of Europe from the 11th century through the First World War.
Unsurprisingly, writing music at the behest of the world's most powerful rulers resulted in a fair amount of outright pandering. "Charles, you were mighty when only a king," reads a snippet from "Carole magnus eras" by Clemens non Papa. Or this, from Heinrich Isaac's "Virgo prudentissima: "Our prayers and entreaties for the sacred Empire and for Maximilian the Emperor." It is much to the composers' credit that in the face of such sycophancy they produced wonderful music: bold and flamboyant in the case of the Clemens, alternately ornate and static in the Isaac.
For all the program's ceremonial grandeur, its most eloquent moments came in lamentational works, such as Josquin des Prez's "Mille regretz," with its austere four-voice texture. In an act of homage, Nicolas Gombert took Josquin's melody and fashioned the text into a more involved polyphonic motet without losing the darkness of the original. Perhaps most affecting was Alonso Lobo's "Versa est in luctum" ("My harp is tuned in mourning"), with its slow-moving harmonies and almost radiant sense of despair.
Stile Antico sang the Lobo with an unerring, lyrical feel for the music's phrases, sustaining them while retaining transparency and rock-solid intonation. The ensemble showed similar virtues everywhere else in the performance: The unexpected roughness that I heard last year had vanished, and the group is again at its vital best. The singing creates a glorious sonic tapestry, but the depth of collective musicianship reminds you that these works, even those aimed at flattering the powerful, are not merely beautiful sound but something akin to living organisms.
As always, the group received an enthusiastic reception from the well-filled but rather frigid St. Paul Church. For its sole encore, Stile Antico put aside matters of political power and sang William Byrd's quiet little masterpiece "Miserere mihi Domine."