Boston’s preternatural distinction in choral singing is well known, so the standard is high for visiting vocal ensembles. One of those that met the benchmark is Ensemble Plus Ultra, a small, conductorless British group that made its US debut here two years ago, sharing a concert with local favorites Blue Heron. They returned on Saturday, with a program all to themselves in the Boston Early Music Festival series.
Ensemble Plus Ultra’s chief focus is on Spanish music of the Renaissance — particularly the works of Tomás Luis de Victoria, much of whose sacred music they have recorded. Saturday’s program made for an intriguing history lesson. Its first half centered on three composers influential on Victoria: Cristóbal de Morales, Francisco Guerrero, and Bernardino de Ribera. The second half was devoted to Victoria himself.
There were plenty of connections to be made. The delicate word painting in a Morales Lamentations setting sounded like a precursor to Victoria’s incisive handling of texts. So did Ribera’s breathtaking “Rex autem David,” a psychologically vivid portrait of King David mourning his son Absalom.
When the program shifted from the predecessors to Victoria’s own music there was an unmistakable sense of disparate elements being fused into a compositional whole. Individual melodic lines grew more florid, the imitation more subtle, and the invention seemed to flow with uncanny ease. In “Vadam et circuibo civitatem,” the composer played ingeniously with light and dark textures, and the music’s restlessness aptly suited a text about seeking one’s beloved.
For a program packed with unfamiliar works, it seems odd to focus on one of Victoria’s best known. But Ensemble Plus Ultra’s rendition of “O magnum mysterium,” with just four singers, may have been a shock even to those who have heard small-size groups perform it. Rather than the expected rich, dark tone, here was the sound of quiet wonder and authentic mystery.
That austerity is part of Ensemble Plus Ultra’s musical complexion. The group has just seven members singing one to a part, and the sound is narrower, more willowy, than other groups proficient in this literature. That made you focus on individual voices rather than on the blend of the whole, and the acoustic of St. Paul Church sometimes made them sound somewhat distant. But they showed a wonderful ability to alter a vocal texture for expressive purposes, even with small forces. And when needed they produced a warm, luminous sound, as in Guerrero’s “Beata Dei genitrix” or Victoria’s “O quam gloriosum,” the sole encore.
Two other British Renaissance vocal groups, the Tallis Scholars and Stile Antico, have become regular Boston guests, and will appear in the BEMF series later this season. One looks forward to Ensemble Plus Ultra establishing a presence here as well.David Weininger can be reached at firstname.lastname@example.org.