Chanticleer celebrated Christmas with its special brand of music Wednesday night at the Smithsonian's Baird Auditorium. This 12-man a cappella ensemble produced a full resonant sound, accented by four countertenors and underpinned by bass-clef voices.

Led by music director (and singer) Joseph Jennings, the group offered a rich, beautifully blended rendition of "O Tannenbaum." In "Silent Night," simplicity was the key: The singers softly hummed the melody in unison before beginning the first verse. For the Spanish carol "Riu, riu, chiu," they added a tambourine to enhance the exciting syncopated rhythm.

In Renaissance motets such as Orlando di Lasso's "Resonet in laudibus" and Palestrina's "Surge, illuminare, Hierusalem" the vocalists created elegant polyphonic patterns. In Thomas Stoltzer's "O admirabile commercium," they intoned with simple Gregorian chant before immersing themselves in counterpoint.

Although short solos and duets by ensemble members usually worked well and added variety, the lead singer for "I Wonder as I Wander" suffered from hoarseness, and the soloist for "O Come, O Come Emmanuel" disrupted the plainsong pattern with a twangy, jazzy style of singing. The jazz touches were marvelous when they fit the music, as in the closing medley arranged by Jennings. Here, focusing on spirituals like "Go Tell It on the Mountain," the countertenors soared to the heavens, the basses offered a percussive beat, and the tenors spun supple melodies.