Even though it’s been almost 25 years, I still remember the first time I heard the Nonesuch album Le Mystere des Voix Bulgares, which featured the Bulgarian State Television Female Vocal Choir. I was already predisposed to like strange new music, but this took strangeness into dimensions I’d never imagined. The performances were rooted in Bulgarian folk traditions and were like nothing I’d heard before. The voices had a keening, piercing quality that was distinctly nasal by Western standards, but at the same time beautiful and pure. The music was modal, but not the familiar Western modes, and it had lushly dense, exotic harmonies and a level of dissonance that could make your head spin. Even though the performances sounded wild and emotionally raw, the choral singing was absolutely disciplined and focused. I was immediately hooked. So were a lot of other people, because that album and the group’s subsequent albums were big sellers in the classical and world music markets.

I remember wondering even then what it would be like to hear men singing like that. The emergence of Basiani, a men’s choral ensemble from the Republic of Georgia (which apparently shares some folk traditions with Bulgaria, even though the two are separated by the Black Sea) provides a happy answer to the question: they can sound really wonderful. The group, founded in 2000, is dedicated to the preservation of Georgian folk song and sacred music. The penetrating timbre of Basiani’s singers has a visceral punch that can be almost shocking to Western ears, and the use of yodeling, chanting, drones, unpredictable harmonies, and elaborate layering of idiosyncratic modal melodies is a reminder that this is a musical culture far removed from Western traditions. Its unfiltered emotional urgency is likely to send a shiver down the spine.

Basiani’s program features a mix of sacred music and folk songs that include achingly mournful ballads, festive wedding songs, and rambunctious traveling songs. Many are polyphonic, meaning that lots of melodies are going on at once, with lines interweaving in gorgeously rich textures. The liturgical songs can be traced to traditions more than a millennium old and are related to the music of the Byzantine Church, and the music’s very distant roots account for its raw, primordial remoteness. At the same time, its complex, sophisticated harmonies and use of extended vocal techniques make it sound surprisingly modern. Stravinsky cited Georgian song as the music he considered “really modern and contemporary.”

Basiani’s only previous appearance in the U.S. was in 2010 at Lincoln Center’s Mostly Mozart Festival, where it was widely praised for its freshness and vigor. The group’s Ann Arbor performance, on October 4 at St. Francis of Assisi Catholic Church, sponsored by the University Musical Society, marks its Michigan premiere.