A stand-out among the competitive and highly individualistic self-presenting groups around town, Exsultemus Period Vocal Ensemble has been gracing the Boston music scene with a good number of attractive programs each season. Some concerts feature just the singers, others pair them with young instrumentalists secure in their own promising trajectories into the limelight. Promoting performances of even the familiar a cappella repertoire is no stroll in the garden. The trio of concerts just completed in two less familiar venues and one first-tier one, at First Lutheran Church in Boston’s Back Bay on January 15, is a good example of this.

The Lamentations settings with which the 16^th century Catholic lands were so enamored are music of profound introspection and unrelievedly heartbreaking tone. They are tough to interpret with consistent engagement and challenge an ensemble’s variety of approach. The scores’ sustained somberness paints from the darkest emotional palette in music. Infrequent quicker passages now and again relieve the affective torpor permeating these most earnest texts in the Roman liturgical year. The Biblical passages are an extended invocation of the destruction visited upon the first Temple by Nebuchadnezzar in his taking of Jerusalem. At the same time, they’re a darkly keening evocation of the dire Paschal tragedy, a presage of crucifixion and torment. No D-major Resurrection crooks a finger, tendering hope of honeyed eternity. This is dour sacred material. The music mirrors the subdued, painful tone of the Biblical texts.

The Lamentations genre sparked some of the most ethereal choral tone painting to come out of the late 15th century. The next century embraced this tradition with its own brand of fervor, especially once the Counter-Reformation took well-funded wing. Exsultemus’s substantial program opened with one of the most beautiful, and one of the least static, settings, Heth, cogitavit Dominus by the brilliant Antoine Brumel, an incomparable colorist and weaver of vibrant harmonic tapestries, here for four male voices. On its heels was an intensely beautiful six-voice (mixed) Lamentations by Robert White. It became clear what narrow emotional bounds the evening would explore and what this would ask of the singers.

The opulent eight-voice scoring of Pierre de la Rue’s Considera Isræl promised a degree of richness; instead, it introduced a quiet severity early in this evening, with held-back harmonic clashes and touching emotional intimacy as the text depicted grief-laden vignettes in the fatal Philistine visitations upon Israel. De la Rue, a cherished contemporary of Josquin, made every brush stroke on the canvas of this anguished motet visible, touching. Exsultemus’s otherwise exemplary focus and intensity elsewhere in the concert faded somewhat in bringing this demanding work to life, then surged back to infuse the powerfully shifting harmonic soundscape of Incipit Lamentatione Jeremiæ Prophetæ (III) by adoptive Briton Alfonso Ferrabosco. A Bolognese native who ricocheted between Roman, London, and Lorraine employments, he owned an exceptionally distinctive compositional voice that embraced grating textures when they mirrored the text, fleetingly caressed the sweetness of a momentary clean resolution, then hurried on in impassioned, entwined sweeps of choral sound. Exsultemus’s fine reading of this extrovert evocation of official churchly grief concluded the first half.

At this point, it is appropriate to comment that our native habit of carpeting—heavily carpeting—churches is among our most anti-musical traits as a people. In the Union Church of Waban, the ensemble’s beautiful tuning and ensemble entrances, its well-judged dynamics and finishes at the ends of phrases, were exposed to the acoustic equivalent of actinic prison lights. Entirely dead acoustics cannot flatter music making, though wall-to-wall Burgundy and sumptuous cushions may impart a sense of lounge-like comfort to congregations. Exsultemus merits applause for its effective battle to be heard in beauty. Its professionalism and rigorous preparation allowed not a crack in ensemble.

The concluding three works, bearing in mind the narrowness of affect the

lamentations as a type imply, thrice surprised listeners. One of Spain’s itinerant a cappella masters, Pablo Bermúdez, left both complete and partial motets and settings in cities as far from each other as Málaga, Puebla, Guatemala, and Granada. His incomplete Incipit Lamentatione Jeremiæ Prophetæ, in which multi-voice blocks of homophony within the erring polyphonic strands impart a sustained state of reflection, offered moments of luminosity and painterly meticulous evocation of the text. No greater contrast with the Bermúdez can be imagined than the penultimate, madrigalesque  secular Venetian lament by Andrea Gabrieli, papa to Domenico. Sassi, palæ, sabbion is a brief, exquisite jewel, the cheeriest evocation of the departed —much-loved San Marco mæstro di cappella Adrian Willært – of the evening, and perhaps of all 16^th-c. polyphony. Exsultemus’s quintet launched into this grechesca with mild abandon, lavishing care and expression on the sonorous, gently swirling Venetian dialect, no doubt enjoying relief from the grays and shadows of the rest of the program.

Who but Palestrina could wash a final setting of Incipit Lamentatione Jeremiæ Prophetæ in luminance and radiance? The stylistic intensity of the preceding Lamentations faded away with the first filigrees of this 8-voice jewel of the genre, a view of the text that allows for, even summons, the notion of hope amid the bleak linguistic pedestals upon which perch all the tragedies implicit in the Jeremiads.

Exsultemus, undeterred by the unfortunate acoustics in which it sang, simply glowed throughout this difficult and demanding program. The group’s comfort in the music and its delight in its unfolding was communicated to the audience, who rather liked what they heard.

Veteran recording engineer Christopher Greenleaf collaborates with chamber, early, and keyboard musicians in natural acoustic venues on both sides of the Atlantic. He is active as a writer, translator, photographer, and acoustic consultant.