Bach’s masterful B-minor Mass was much beloved and often programmed by Bach Festival co-founder and longtime Artistic Director Helmuth Rilling. So, when Artistic Director Matthew Halls opened the Festival with the piece last night, he was both brave and wise to give an extraordinarily different, non-Rilling performance in ‘historically informed’ style. Halls led the Berwick Chorus, OBF Baroque Orchestra, and soloists, in offering us a B-minor Mass that was bound to challenge the OBF audience, but rewarded listeners with exquisite musicianship and a deep meditation on Bach’s musical genius.

For a listener used to hearing modern orchestras playing modern instruments, it takes a good long time–maybe the better part of an hour–for the ear to adjust to period instruments and style. During this acclimatization, the effect can be frustrating, even aggravating, like someone kissing you gently when you want them to kiss you…less gently, or like eating a lovely meal that, you think, would be really delicious if only you could put some more salt on it. Once your attention adapts, though, the experience dramatically shifts. That gentle kiss is full of tender nuance and sensation. The food reveals marvellous flavors you just didn’t notice at first.

To heighten the challenge, while last night’s quiet instruments may have been of period 18th-century style, the Silva Hall is decidedly not. Bach’s music would have been performed in lively, even echoing spaces, where one note could hang in the air and blend into the next one. The Silva, on the other hand, is famously sound-absorbent. What to do? Halls responded to the acoustic challenge with a tour de force of precision and clarity, giving the evening the virtuosic intimacy of a chamber music concert. For those willing to make the aural adjustment, Halls’ direction offered breathtaking feats of texture and color, and gave artful structure to each chorus, aria and duet with the most subtle dynamic shaping.

Through a kind of creative alchemy, Halls pours the sounds of the OBF Baroque Orchestra and the Berwick Chorus into one another in a way that modern instrumentation cannot allow.

For singers, ‘historically informed’ performance means trading broad vibrato for a purer tone, which allows Bach’s harmonies to ring with celestial perfection seemingly right inside your brain. Baritone Morgan Smith was particularly fine in the Quoniam tu solus sanctus, accompanied adroitly by Andrew Clark on corno da caccia (an ancestor of the modern French Horn.) Also noteworthy were the otherworldly trio between tenor, cello and flute in the Benedictus and the delightful, confection-like violin/soprano duet in the Laudamus te. The Berwick Chorus displayed astonishing dynamic control throughout the Mass. At the burial of Christ, for example, the singers sustained a pianissimo so delicate and pure you weren’t sure whether you were hearing it or just feeling it like a gentle breath of air.

The B-minor Mass is a perfect fit for this year’s Festival theme, “Take the Journey.” It creates a musical universe encompassing intricate fugues and dreamlike melodies, heavens-bursting trumpet blasts and delicate duets and trios. The journey has a meditative end, not a showy one: The final aria, a haunting Agnus Dei (sung beautifully last night by countertenor Christopher Ainslie) fades into the gentle swelling and transcendent peace of the closing Dona Nobis. We are left to contemplate the message Bach has left us at end of a very long, visionary life of searching deeply into beauty, and into God.

Music nerds would have appreciated being able to follow a listing of all twenty-seven choruses and arias in the program rather than just the eight sections of the mass. Also, the program lists the obbligati and continuo instrumentalists by name, while the rest of the orchestra is credited as “OBF Baroque Orchestra.” The members of the Berwick Chorus are listed by name later in the program, but this reviewer could not locate a similar list of the Baroque Orchestra musicians. Having dedicated their lives to the perfection of their art, and having played like a veritable band of angels in the Silva Hall last night, they deserve to be clearly credited.