Peer closely at the program for the Con Brio Society's Christmas Concerts, taking place Friday and Sunday at Christ the King Church in Old Lyme, and you'll spot a piece by contemporary Norwegian composer Ola Gjeilo. I'm not the biggest go-to source for reputable knowledge on present-day classic music — typically I'm right behind Attorney General (and ace oboist) Matthew Whitaker in that context — but methinks this Gjeilo guy is really good. Given the time of year, check out his "Winter Songs" album.

The Society is performing Gjeilo's wonderful "Serenity (O Magnum Mysterium)" — original music  to that timeless Christmas Matins chant — but that's only a small part of an impressive evening of music. The headline piece will be a rendition of Jan Zelenka's rediscovered Baroque masterpiece Te Deum, and also slated are J.S. Bach's Christen ätzet diesen Tag, (BWV 63 — first movement); Matthias' Sir Christèmas; Rutter's What Sweeter Music; Biebl's Ave Maria; and an arrangement of "I Saw Three Ships."

In addition to Con Brio's surperb choral blend, they'll be ably supported by the Con Brio Festival Orchestra as well as sopranos Danielle Munsell Howard and Louise Fateaux and mezzo-soprano Allison Messier.

Con Brio Society's "Christmas Concert," 8 p.m. Friday and 3 p.m. Sunday, Christ the King Church, 1 McCurdy Lane, Old Lyme; $30; (860) 526-5399, conbrio.org.