With its mosaic icons all round the walls, St. Demetrios Greek Orthodox Church in Montlake is an ideal place to hear Portland’s Cappella Romana, a choral group devoted to scholarly performance of the music of the Eastern Orthodox Church, both contemporary and going all the way back through the history of that church.  It’s the only group in the world, it states in its notes, producing complete programs of medieval Byzantine chant, researched by scholars and sung from editions prepared from the original manuscripts.

Sunday afternoon, the ensemble presented Mt. Sinai: Frontier of Byzantium, with music from the ancient Holy Monastery of St. Catherine (founded by Justinian in the mid-sixth century in the Sinai desert). Cappella Romana returns to Seattle in January to sing Rachmaninov’s All-Night Vigil.

Ten male singers took part, of whom four mostly sang drone underneath. The remaining six are each a cantor, or psaltis, of Greek Orthodox churches or cathedrals in Roslindale (Massachusetts), San Francisco, Atlanta, Portland (Oregon), Tinos (Greece) and Oxford (England). All are deeply steeped in this music and in the church’s services.

I mention this because, if you have ever heard recordings of Gregorian chant—the most commonly available—sung by a first class choir, or by monks, there’s a difference. The choir may be impeccable, but the monks bring to their singing something deeper which can leave a profound effect on the listener. The same if you go to hear Tibetan monks chanting, and the same goes for Cappella Romana when these cantors are singing.

They sang a group of chants from the 14th to 16th centuries, first The Vespers of St. Catherine, then The Service of the Furnace, an account of the three holy young men thrown into the burning fiery furnace, emerging unscathed.

All the words are printed in the program, in both Greek and English, but unless you can read Greek, it is almost impossible to know where you are in the program. The ensemble sang each half of the program uninterrupted, with applause only at intermission and the end, which prevented any feeling of fragmentation.

The chant for the Vespers is largely contained within a narrow middle vocal range, with occasional forays above or below, reaching a higher range for the Furnace service. The men sing in unison with a strong drone underneath, and there is little change dynamically. This does not make it dull. Anything but. The sound is fullbodied and sonorous, sturdy, steady and vigorous, open and weighty without vibrato, almost hypnotic. It’s also easy-sounding, as it would have to be to preserve voices which may be chanting for hours.

There is emphasis, often at the beginning of a phrase and marked by coming to the note from underneath. Each singer sang solo phrases from time to time, answered by the others, and often there were antiphonal sections with three singers on one side alternating with three on the other. Long melismatic lines, and brief ornaments embellish the chant, which uses an ancient scale. Tempos are four square, but flow within that. Often it’s the pace of a measured tread, at times it rose to a fast walk, yet there was always a buoyancy to the singing.

At the end, as encore, the men sang a modern setting in English of a hymn to St. Catherine. It was enlightening to hear how similar it was, the same ornaments in a unison melody over a drone. I left with a sense of refreshment and peacefulness.