The world is full of great touring choral ensembles, and the Cathedral Basilica of SS. Peter and Paul has been filling a significant niche by importing them – with a catch. Though the Basilica is one of the most beautiful public interiors in Philadelphia, the acoustics are more akin to 30th Street Station. What to do?

The season opener on Saturday was the all-male, eight-voice, genre-crossing Cantus – a clean-cut ensemble from the Midwest that is said to eat cathedral acoustics for breakfast. And that, amazingly, turned out to be true. The solution: unforced but intensely focused singing. Greater quantities of sound would've just ricocheted around the space, while smaller, low-vibrato, tightly blended voices, meticulously balanced with subtle treble highlights from high-range tenors came through with a clarity that I've never experienced there.

The title of the concert was Discovery of Sight, a poetic concept rich in visual imagery with music by a range of composers that might not have worked under less carefully curated circumstances, and perhaps the precedent of Chanticleer (which arrives at the Basilica next April 28). Heavyweight moderns such as Gabriel Kahane, middleweight figures such as Einojuhani Rautavaara and Eric Whitacre, lesser-known but thoroughly welcomed names such as Jean Émile Paul Cras, and folk songs (from American to Japanese) flowed together, the main uniting factor being that high-personality trademark sound.

However exquisite, the sound was successfully altered for the more unvarnished harmonies of Schubert's "Wie schön bist du" (probably written for an amateur singing society) as well as for the harmonic sophistication of Richard Strauss' "Ein Licht im Traum." All Cantus members are credible soloists, which was good for incidental solos and drone effects that harmonically anchored any number of passages. They sing rhythm, not emphatically, but enough to suggest, in the spirituals at the end, that they have a bit of doo-wop in their veins. The only performance that had less than 100 percent clarity was Kahane's "Coffee With Borges," which has musical gestures leaping out in many different directions (interesting!) but didn't have the most intuitive word settings.

Words were a big part of the concert, maybe too much so. The music may well have been chosen partly on the basis of the texts by Emily Dickinson, Dylan Thomas, and T.S. Eliot. Composer Rautavaara wasn't at his best with Eliot texts, though the words were set with sensitivity. Traditional selections such as "Simple Gifts" and "Morning Has Broken" might seem like a step down from the rest of the program were it not for the arrangement with the kind of harmonic ambiguity that made phrases land in unexpected but pleasant places.

Every few songs, though, came a homily of sorts from a different Cantus member, some of them introductions to the music, others with heady quotations by the likes of Carl Sagan, explanations of how eyesight works and a sprinkling of nondenominational bromides that wouldn't be out of place in TED Talks. But for listeners who are truly in the thick of life-changing issues, talk is a mere prescription while music is the remedy.

The next Concerts at the Cathedral Basilica event is the Westminster Williamson Voices on Nov. 19. Information: 215-561-1313 or