Chanticleer’s collective power

With a program called “A Chanticleer Christmas,” you come expecting the vocal ensemble to heed the muse of variety rather than artistic cohesion, which was clearly the case Saturday at the Irvine Barclay Theater. This stellar 12-man vocal group celebrates its 25th anniversary this season, having carved out success with the ample power of its collective voice and a freewheeling diversity.

So nobody blinked much when the program ran from lustrously rendered early music to elegant responses to the caroling imperative. Chanticleer opened on a movingly austere note, singing 13th century plainsong in candlelight and formal attire, and ended in casual Perry Como-esque sweaters, with an encore of Vince Guaraldi’s “Christmas Time Is Here.”

Chanticleer gets away with variety shows like this because of the renewable joy of hearing its unerring vocal mesh and the obvious depth of musicality. Plus, the holiday spirit is forgiving.

Although they opened the second half of the concert with the soothing “Ave Maria” by German composer Franz Biebl (1906-2001) -- which they have popularized -- it was the “Ave Maria” of 500 years earlier, by Josquin Desprez, that left a stronger impression. Exquisitely interwoven voices conjured up a timeless beauty, as it also did on Praetorius’ sublime “In Dulci Jubilo.”

Splitting the difference between early and contemporary music, the very alive and thinking British composer John Tavener was represented by a few pieces, with his usual reconsidered antiquity. In the carol department, Chanticleer drew on smart versions, arranged by the likes of Ralph Vaughan Williams and David Wilcocks. Still, this segment seemed to risk floating away from earlier seriousness.

Musical director Joseph Jennings’ arrangement of spirituals saved the day, a refreshing deviation from the yuletide norm, sung with convincing soulfulness.