The Christmas concert of The St. Mary Schola, Tuesday night at the Cathedral Church of St. Luke in Portland, was, as usual, carefully programmed and angelically sung. This year’s musical offering also included a baroque ensemble — violins, viola, recorders, cello, and viol da gamba — tuned to “old pitch,” usually A-415 Hz, as compared to the A-440 Hz pitch of the modern orchestra.

The half-step down sounded authentic, and enhanced the baroque works on the program, as if they were happy to be home with loosened strings. Cheerfulness was the mood of the evening, with not a Gregorian chant in sight.

Director Bruce Fithian has built the choir of 14 around six voices, soprano, mezzo soprano, tenor, counter-tenor, bass and baritone, an ideal configuration for both renaissance and baroque choral music. Orchestral accompaniment allows them to sing at perfect intervals, like an a cappella chorus.

The most marvelous example of this was the “Videte miraculum” of Thomas Tallis (c.1505-1585) which constructed a gothic cathedral of interwoven voices.

The highlight of the evening was the “Messe de Minuit” by Marc-Antoine Charpentier (1645-1704), the most lighthearted Mass I have ever heard. Written for Christmas Eve, it incorporates many French Christmas carols of the 17th century into the traditional Mass.

The only section not based on carol tunes is the credo, but even here songs celebrating the arrival of Noel are contrasted in the final stanzas with the more mysterious music depicting the incarnation. The “et in Spiritum sanctum” positively soared, and the Agnus Dei was pure caroling to a dance-like three-beat rhythm.

Charpentier’s Mass was charmingly sung throughout, with a perfect balance of voices and the instruments of the full ensemble. The recorders were particularly effective, imitating shepherds’ pipes in the Agnus Dei.

The singing of the full choir was interspersed with solos, duets and trios, all of them serving as welcome highlights. The trio of baritone, tenor and counter-tenor produced some spine-tingling sounds, as did a duet of soprano and mezzo-soprano.

The first part of the concert, devoted to anticipations of the Coming, was sung primarily in German, with a “Wachtet auf” by Dietrich Buxtehude (c.1637-1707) so rousing that it prompted an ovation, despite a request to hold applause until the end of each half.

The second part, with works in French, German and English, celebrated the Birth itself.

The music was interspersed with highly appropriate readings, by Andrea Myles-Hunkin, from Matthew Arnold to the great Persian poet Rumi (1207-1273).

Fithian sang tenor, conducted and provided continuo on a chamber organ. I wonder how he contrived to match the fixed organ notes to the A-415 tuning of the other instruments. If he transcribed everything a half-step down, that would have been another musical feat.

Christopher Hyde’s Classical Beat column appears in the Maine Sunday Telegram. He can be reached at:

classbeat@netscape.net