Why do Bach’s iconic cello suites, written three centuries ago, remain so enduring today? That Bach’s brilliance is timeless, while true, seems to me a bit facile, and not specific enough. These pieces present enigmatic contradictions, posing special challenges for a performer and requiring unusual attention and immersion for a listener. The core of Bach’s musical world, as would be expected in the cultural and social climate of his time and place, was his deep religious devotion and service to the church, and yet these works, among other equally secular masterpieces that he composed during an especially fruitful period in Köthen between 1717 and 1723, achieve a profound intimacy exceptional even for his genius.

There is no dramatic ecclesiastical narrative in these stylized dances — this is Bach at his most abstract, which might account for why the music seems to demand such focus from the listener. Bach’s mastery of complex counterpoint, on virtuosic display in so much of his music, from large-scale choruses to his solo organ works, does not seem at first hearing to be at the heart of these suites. And there is no question that there is the appearance of less polyphony in the cello suites than in his solo sonatas and partitas for violin, which date from the same period. In the cello suites, there is less that is explicit, more that is internalized. Nevertheless, the counterpoint in this music, the backbone of everything that Bach wrote, is in no way less sophisticated or developed.

Michael Stern leads a rehearsal of musicians from the Kenwood Academy and Civic Orchestra with Yo-Yo Ma on June 9, 2017. | ©Todd Rosenberg Photography 2017

Therein lies, perhaps, one of the secrets of these works’ power, and why it strikes me as essential music for us in the 21st century. Much of the counterpoint is implied, left for the performer to make those suggested connections clear and for the listener to fill in the longer line. There is a very practical reason for this, a challenge that Bach must have embraced intentionally when he chose to write such soloistic and difficult music for the cello, which had been until then used only as an accompanying instrument to support a melody or reinforce a realized figured bass. It is difficult enough to produce three or four tones simultaneously on a violin. On a cello’s longer strings, the distance between the notes requires a greater stretch of the hand to move between them, and the gaps between the strings require more time to make those connections.

Furthermore, Bach left little by way of direction for interpreting the phrasing and dynamics, or even the speed or pulse of the music. Outside the dance titles, there are no indications even of tempo. The contrapuntal direction, the harmonic motion and the form in the purely melodic movements like the Gigue in the E-flat Major suite, or the Sarabande in the C Minor suite, are all clear, but not fully spelled out. The implied connections, hidden polyphony and artless expression require exceptional creativity from the performer and engagement from the listener, establishing an unusual relationship between cellist and audience.

Transcending even Bach’s profound devoutness, these works are statements of faith pared down to their purest essence. When Yo-Yo Ma asked me to write these few sentences, it gave me the opportunity to reconsider both the music and his approach to it. It is sometimes difficult to be objective about a friend with whom one has been close since earliest childhood, as is the case with Yo-Yo and me. It has always been clear to me that his generosity of spirit as a musician has been fueled by the two impulses essential to understanding these works: boundless curiosity and a fervent need to communicate

Yo-Yo could play every note of the suites from memory even before he and I met, 55 years ago. Since then, he has continually searched for the music that happens between the notes, and the mysterious and private nature of these works now fuels his fertile creativity with even deeper breath, with even more disciplined freedom and unhurried insight. The stylized dances that animate the pulse of these movements were not meant to accompany actual dancing — and similarly, and to a large degree, they seem not really meant for public performance. Even at their most joyous, the music seems ill-suited to extroverted or public display, and at their most meditative, the suspension of breath and time is so intimate that listening to them can feel akin to eavesdropping.

And still, their communicative power and touching humanity can bring thousands of silent and rapt listeners together into a mesmerizing communion with Bach. This is private music but amidst the noise of our time, I am convinced that the private conversation has never been more urgent and vital.

Michael Stern, music director of the Kansas City Symphony, is Yo-Yo Ma’s lifelong friend and colleague. These reflections by Stern, written at the start of the Bach Project in August, are adapted from the liner notes to “Six Evolutions: Bach Cello Suites,” Ma’s recording of the suites, available from Sony Classical.

TOP: Michael Stern and Yo-Yo Ma share an embrace of artistic brotherhood after a rehearsal. | ©Todd Rosenberg Photography 2017