Silhouetted against the backdrop of gently shattering waves of the Atlantic they crossed, long-established German duet partners violinist Christian Tetzlaff and pianist Lars Vogt had an artistically unbuttoned presence at Rockport’s Shalin Liu Performance Center on Sunday. Superlatives have come easily for Tetzlaff over the years, and it is not difficult to see why. His playing is free, underived, axiomatic, and honest. His approach is at once materially cerebral and anti-computerized—a marriage between function and sound. For him, beauty is not linked to perfection, and neither is it a fragile vase. To borrow a term from Nassim Nicholas Taleb, his playing is “antifragile”, that is, any lack of “perfection” functions as a boost in resilience and capacity. As a result, any minor errors feel volitional and are, as James Joyce would say, “the portals of discovery.”

Written during the torment of his increasing deafness, Beethoven’s Sonata in C Minor Op.30 No.2 for Piano and Violin was a move towards the heroic sounds of his middle period. Tetzlaff and Vogt played it with considerable thrust, moving from the gentle rumble of the opening to the sturm und drang of its furious cadence without compromise. The Adagio came across more delicate than sweet, and maintained an Andante-like momentum. Slower moving material reveals Tetzlaff’s strengths, as he has an uncanny ability to turn it into art-song. In the very successful Scherzo,  the duo never missed an opportunity to parody themselves. Tetzlaff’s execution of accented notes elicited visceral sensation that I seldom feel from other violinists. I felt the components: a heavy front of the note, and its broad sustain, rather than one brutish clubbing motion which many employ to show dynamic contrast. In the finale, Tetzlaff and Vogt took no prisoners and finished the sonata with a febrile confidence. While some may prefer the spacious long lines and luscious sound of a Henryk Szeryng [here], the destabilizing spontaneous combustibility of this duo utterly convinced us.

Bela Bartok’s Sonata No.2, Sz.76 goes beyond any of Bartok’s previous works in that its use of folk themes and style (a common trait of Bartok’s music) is convoluted by the use of all 12 tones, rather than the typical 3-5 used in most folk tunes. Additionally, the score is more complex and exacting, foreshadowing a growing trend, as seen in subsequent works like George Enescu’s 3^rd Violin Sonata. Vogt excelled in this, showing great strength and sensitivity. Tetzlaff traversed the work’s alien landscape with avery wide palette.

The duo cut the intermission short, beginning Mozart’s Sonata K.377 in F Major before the audience could completely sit and quiet down. It was somehow inviting, just like the spirit of the music. Their charm in the Allegro could make you miss both repeats. Mozart intended for this music to be keyboard-centric, and while Vogt was commanding with the amount of sound and contrast he produced, Tetzlaff’s sound was more often the attraction. Typically the most challenging to pull off, the theme and variations of the 2^nd movement was beautifully rendered. Each variation unfolded as a chapter of a story.

During the opening of Schubert’s Rondo in B minor D.895, I was reminded of late 19th/early 20^th-century German violin playing [here]. Articulations and contrasts were direct, accents were agogic, and vibrato was thin and minimal. Tetzlaff’s tone was not the most luxurious, but his silvery sound aided him in creating agile phrases. Particularly striking were several moments where he sustained one note above Vogt’s active piano line. Using no vibrato, his bow technique was so detailed that he sounded just as active as Vogt. In the Rondo itself, Tetzlaff and Vogt delivered the fervor and unbridled joy that Schubert’s writing demands. The duo’s expression was constantly in flux. This is a rather trendy conception in recent years but can be disorienting after an hour, leaving the listener unsure and a bit numb. However, Tetzlaff and Vogt always kept themselves grounded and achieved a hypnotic effect without any hint of histrionics.

There are two kinds of violinists—the kind that say “I am going to reveal the potential of the violin like no one has ever done before” and the kind that say “I am going to play with as much meaning for the eye as for the ear, and not to delight the eye, but when you contemplate it, your imagination can invent sonorities, maybe even sonorities that don’t now exist.” Tetzlaff belongs firmly in the 2^nd camp, and even the duo’s rather ‘violinistic’ encore, the gorgeous Ballada from Leoš Janáček’s Violin Sonata, fantasized subtle shadings and intimate vibrations. At times, the tone Tetzlaff pulled from his modern instrument (built by Peter Greiner) hovered in midair. While it is rare to see inner movement of a sonata selected as an encore, it ended the afternoon’s journey in an exquisite moment.

By the end of the program I had the feeling that I could just hand Tetzlaff any instrument, and he would play it, or that if he woke up one morning and could not play the violin ever again, he would simply pick up an oboe or bassoon, take a year or two, and continue where he had left off. Tetzlaff just happens to be a violinist. The great Fritz Kreisler famously admitted to practicing a mere 30 minutes a day on average throughout the bulk of his later career, and I suspect the same is true of Tetzlaff these days. Having achieved an elite technical fluency early on, the two couldn’t be more different in their conception of the violin’s sound and purpose, but they share the need to spend time living with the music that touches them most and creating a unique and identifiable soundworld. Likewise, Tetzlaff too enjoys performing the same work many times. Reportedly his Beethoven’s Violin Concerto outings number over 300 times. Generally, artists avoid such repitiousness for fear of plateauing to stale and tired interpretation. For most, such a feat would be purely athletic and professional, touring a warhorse from city to city to wow new audiences.

Maybe it’s the advent of iTunes and YouTube which can disgorge 300 similar renditions of the Beethoven concerto, discouraging artists of high aspiration from simply repeating technical feats from one city to the next. Maybe it’s the fulfillment of the prophecy of Glenn Gould (and others), that all of the standard interpretations of great works will soon be exhausted, forcing musicians to create new values and evolutions of the artform. In any case, for Tetzlaff and Vogt, the music of great composers is indefinitely renewable, and they venture beyond the surface appeal of pleasant robust sound and technical wizardry for its own sake. We are lucky that the frustrating wall between great artists of America and Europe is starting to dissolve, and the audience on Sunday afternoon agreed, as they warmly received the inspired imagination and flux before them, just as they watched sun set behind the seductive danger and repose of the ocean.

Daniel Kurganov is a violinist and educator based in Boston. In addition to regularly performing worldwide, he is devoted to furthering the understanding of style, technique, and exemplification in musical practice, as well as expanding the tools of a musician through technology and cross-cultural reciprocity.