Summertime and the living is easy? Not at Ravinia on Tuesday night where the Juilliard Quartet gave riveting performances of rigorous works of Bartók and Beethoven. The quartet’s annual Ravinia appearances are routinely rewarding, and Ravinia is certainly of significance to them, as it was the chosen venue for violist Samuel Rhodes’ final performance before passing the baton to incumbent Roger Tapping in 2013. Another personnel change has occurred since I last saw them, with cellist Astrid Schween becoming the quartet’s first female member in their seven decade history. One would have thought the four had been playing together for many years, however, as their chemistry was utterly palpable.

The evening opened with Bartók’s String Quartet no. 1 in A minor. The Juilliard Quartet has long been associated with Bartók’s six works in the genre, having made pioneering early recordings of the iconoclastic cycle which are still considered benchmarks. The First String Quartet was written simultaneously with the First Violin Concerto; both express the composer’s (largely unrequited) feelings for the violinist Stefi Geyer, and share a common theme, introduced in the quartet in the opening material for the two violins and exuding a pained lyricism. The movement’s primary theme was carried largely by first violinist Joseph Lin in the upper register of his instrument, and the quartet played with a red-hot intensity that never waned.

The winding Allegretto gave matters a bit more movement than the preceding section, punctuated by an occasional pizzicato ostinato in the cello. It was often hard to believe that there were only four musicians on stage, given their rich orchestral sonority of immense power. Following a brief introduction, the finale was marked by mechanistic repetition in the violins and an angular theme in the low strings. Solo passages for the viola afforded Tapping some time in the spotlight, and the quartet closed the work with feverish concentration.

The remainder of the program was devoted to Beethoven’s incomparable late quartet, String Quartet no. 13 in B flat major. Not ones to skirt a challenge, the Juilliard Quartet opted for the original ending, namely the daunting “Große Fuge”. Abrupt changes between slow and fast sections characterized the opening movement, and a disjointed theme leapt from the strings. The repeat of the exposition was observed, inclusive of the slow introduction, and was revealed to be more than merely an introduction but an integral part of the movement’s architecture. The brief Presto was given with a propulsive drive, and its fleeting evanescence surely didn’t go unnoticed by the young Mendelssohn.

Contrast was to be had in the succeeding slow movement, with a songful melody in the first violin, and I was particularly struck by the sumptuousness of the inner voices. The “Alla danza tedesca” was courtly and graceful, while the “Cavatina” was quite heartwrenching in its harmonious resounding and deep serenity. An arresting opening announced the massive concluding fugue, and matters proceeded with a ferocious energy – so much so that Lin broke a string, as sure a sign as any of the intensity with which he played. This of course necessitated a brief pause while he went backstage to mend the instrument, and the quartet began the finale again – a welcome opportunity, in fact, as the first attempt was marred by a disastrously timed cell phone ring.

Following an authoritative statement of the first fugal subject, the quartet negotiated the labyrinthine complexities with aplomb. Balance was expertly achieved, and there was ample differentiation in each voice – no easy feat given the inherent homogeneity of instruments in the same orchestral family. Dissonance piled upon dissonance, only occasionally mitigated by a calming interlude, and the quartet’s keen sense of the fugue’s large-scale structure guided the listener with clarity to the work’s clangorous conclusion.