For those of you unfamiliar with Bach scholarship over the past decades, there has been bitter contention over the interpretation and performance of Bach’s three great musical compendia, The Art of the Fugue, A Musical Offering and the B Minor Mass. During a session at an American Musicological Society conference in the ‘70s, one of us actually witnessed Bach scholars trading vicious insults and nearly coming to blows over Bach’s intent for the size of the Mass chorus – and this for a work that, as far as we know, was never performed in the composer’s lifetime. Suffice it to say that every performance of the Mass represents some sort of compromise between the available forces, conflicting scholarly opinion and the Platonic Ideal.

Thursday’s performance in Memorial Hall by the Carolina Choir, the UNC Chamber Singers and the UNC’s early music consort Ensemble Courant, plus soloists, under the direction of Susan Klebanow, offered such a compromise. First, the triumph: the chorus was nothing short of fantastic in this, perhaps the most difficult choral work in the repertory. In addition to the usual kudos for precise entrances, perfect intonation, blend and good diction, Klebanow drilled her singers to sing musically, with understanding and respect for the nature of the contrapuntal lines (i.e. knowing when to sing out and when to put a lid on). They sang without vibrato, creating a sound as close as possible to that of Bach’s boy choristers – although he had far fewer of them. Ensemble Courant played about as well as we’ve ever heard them. The soloists — soprano Jeanne Fischer, contralto Mary Gayle Greene, tenor Timothy Sparks and bass Valentin Lanzrein — were also outstanding, especially Greene in the ultra-low register of the Agnus Dei. Fischer’s and Greene’s blend in the Christe eleison was butteryalthough pretty heavy on the vibrato. And Lanzrein had a missed entrance. Of all the soloists, we think Sparks had the best “period sound.”

Now, here’s the compromise. The performance featured a chorus of nearly 100 singers (divided more or less equally into five sections), accompanied by a chamber orchestra of period instruments, 27 strong. The imbalance caused by the lower volume and resonance of early instruments was particularly problematic throughout the massive Kyrie fugues, where the softer oboes, flutes and strings double the vocal parts. Ideally, such an orchestra would have been better suited to a smaller group, say the Chamber Singers alone, performing in a smaller hall. On the other hand, the quality of the instrumental sound, particularly in the arias where instrumental soloists have obbligato roles, would certainly have been less effective with modern instruments. Generally, the heavily concerted sections, replete with trumpets and timpani, achieved a better balance. We regret also that the extensive and informative program notes included nothing about Bach’s orchestra, nor did the program listings indicate the use of period instruments. We know the Chapel Hill crowd is pretty sophisticated, but I’m sure there were many proud parents wondering why the NCS’s principal horn, Andrew McAfee, was struggling with the notes and partials on his natural (valveless) instrument.

But we’re not carping about the compromises. The advantages far outweighed the problems of balance and authenticity. What a wonderful experience for these young singers to have experienced and mastered such a work! If they don’t remember it for the rest of their lives, they should.