Calmus. (Bertram Bölkow)

Holiday concert fever is upon us, and it has taken over the Barns at Wolf Trap. The venue hosted the first stop of a U.S. tour by vocal ensemble Calmus on Sunday night. The program’s theme was “Christmas Carols of the World,” drawn from the German quintet’s new album of the same name.

The first half of the evening aped a celebration of midnight Mass on Christmas Eve, opening with a candlelight procession to an arrangement of the Latin carol “Veni, Veni Emmanuel.” Orlando di Lasso’s setting of some of the Proper texts for the Mass of Christmas Day provided a quasi-liturgical structure. In five parts, this beautiful piece revealed the strengths and few weaknesses of the ensemble, strong as a group if sometimes tentative or strident in individual voices.

In the more serious first half, Calmus favored arrangements (mostly by their baritone, Ludwig Böhme) that were much more than mere harmonizations of these often simple carols, giving a contemporary flavor to the music. Their version of Thomas Ravenscroft’s “Remember, O Thou Man” was particularly effective, featuring bird-like calls between soprano Anja Pöche and countertenor Sebastian Krause.

The ensemble let its hair down for a lighter second half, with arrangements more in the vein of university a cappella ensembles, complete with snapping fingers and imitations of percussion instruments. This sort of stuff can have great appeal, but for me the group had filled its permissible quota of cuteness before it had made it through an overlong rendition of the carol “Silent Night” in five languages. Böhme’s tongue-in-cheek version of “The Twelve Days of Christmas,” which modulated upward with each verse, provided a fun conclusion.

Downey is a freelance writer.