CAMBRIDGE — Every concertgoer knows the curiously comforting sound of string instruments tuning up before a concert, the hall abuzz with the sound of perfect fifths. But for anyone casually dropping in a few minutes late to the Boston Baroque chamber performance on Friday evening at First Church, something might have seemed amiss. The violinist Christina Day Martinson stood in front of the seated audience, wrestling her violin into a strangely contorted tuning, the lowest string ratcheted up perilously high, from its normal G to a C, with its neighboring D string lifted to an E. It might have seemed like preparation for an evening of experimental contemporary music, but in fact, the sonatas soon to fill the church were written by a composer — Heinrich Biber — born in 1644.
Biber’s set of “Mystery” Sonatas — sometimes called the “Rosary” Sonatas — in fact contain some of the most audacious experimentation ever conceived in scordatura, or altered tuning, as the strings of the violin are retuned for each of the 15 works in this cycle, in the process continuously altering the violin’s resonance, the relative brilliance of its sound, and its world of chordal possibilities.
Biber had in mind more than just tuning innovation for its own sake. Each of the sonatas evokes a different event in the life of Jesus and the Virgin Mary, and tuning here becomes an expressive device in its own right, essentially shifting the qualities of the violin’s speaking voice to suit Biber’s reflections on, by turns, Jesus carrying the cross, the descent of the Holy Ghost, the trumpet blasts heralding the Ascension, and so forth. For the perilous 11th sonata — “The Resurrection” — Biber goes as far as requiring the violinist to thread the middle two strings such that they form the shape of a cross behind the bridge. Cumulatively, this set contains some of the most exquisite and dazzlingly virtuosic violin music written before Bach’s Sonatas and Partitas.
It also tends to wreak havoc in the mind of the modern performer, as the music is notated as if the violin were tuned normally, even though the pitches generated don’t correspond with the notes on the page. I once described the cognitive dissonance of playing one of these sonatas as perhaps somewhat similar to that of typing on a keyboard where every keystroke generates the letter located two keys away.
For her part, as Martinson explained to Friday’s audience, she has been working on this music on and off for 10 years. It showed. Martinson assumes a modest presence onstage but this performance was, quietly, a tour de force. Backed by a sensitive continuo group, the violinist traversed with remarkable fluidity and dynamism — and without break — the final seven of the 15 sonatas (having played the first eight last year) as well as Biber’s unaccompanied Passacaglia.
Her playing in each work combined a secure grasp of period style with a fearless technique and, best of all, a delightful sense of spontaneity and imagination. Moments in the exuberant Sonata No. 14, “The Assumption of the Virgin,” tumbled free like a kind of ecstatic folk music. She showed a particular knack for shaping passagework with dancelike inflections, conferring on each line a sense of direction, rhetorical coherence, and expressive intent. No performance of this length and riskiness could be note-perfect, but Martinson’s was nevertheless a triumph, confirming her status as one of the brightest next-generation talents on the city’s bustling early music scene.
For most of the evening, Boston Baroque music director Martin Pearlman provided shapely support at the harpsichord and organ, joined by Sarah Freiberg (baroque cello) and Victor Coelho (theorbo). But the night ended with the sound of Martinson’s unaccompanied violin, in Biber’s Passacaglia, a piece moving in its simplicity and directness. On Friday it arrived as a kind of distilled version of what each of the preceding sonatas must have surely been for Biber, beneath all of their exotic tunings, their vividly pictorial titles, their depictions of earthly sorrow and celestial joy: an invitation to prayer.