A concert of the Borromeo String Quartet in Zankel Hall began with Bach—some preludes and fugues from The Well-Tempered Clavier, Book I. Ever since they were written in the first half of the eighteenth century, the two books of The Well-Tempered Clavier have served as a kind of Bible for musicians.

Players have loved to play them, of course. Listeners have loved to listen to them. But I dare say that The Well-Tempered Clavier has meant the most to composers.

I will quote from a program note by Nicholas Kitchen, the first violinist of the Borromeo String Quartet:

. . . The Well-Tempered Clavier has nourished classical music like the root system of a great tree. [What a great line, and true.] Chopin kept it on the piano as he wrote his 24 Preludes. Bartók meticulously prepared his own pedagogically reordered edition. Schumann called it his “daily bread” . . .

I have always been grateful to Christian Gottlob Neefe, Beethoven’s piano teacher in Bonn—who gave the boy The Well-Tempered Clavier and set him for life. You can hear The Well-Tempered Clavier all through Beethoven’s œuvre, for these preludes and fugues seep into a person’s very bloodstream—certainly the bloodstream of a fellow great composer, such as Beethoven.

You can hear The Well-Tempered Clavier, outstandingly, in Beethoven’s thirty-two piano sonatas. For one thing—one of many—Bach taught composers what to do with keys (C major, C minor, etc.). He taught them what keys were good for, what their nature was.

Here is a memory: In old age, Pablo Casals, the cellist, would begin his day by playing some preludes and fugues from The Well-Tempered Clavier on the piano. His hands were gnarled, but they freed up when playing this music. Furthermore, this playing was evidently a kind of prayer for him.

Nicholas Kitchen has arranged all of Book I for string quartet. (I don’t know about Book II.) And in Zankel Hall, the Borromeo played the first four pairs: that is, the Prelude and Fugue in C major, the Prelude and Fugue in C minor, the Prelude and Fugue in C-sharp major, and the Prelude and Fugue in C-sharp minor.

You know? You could do a lot worse. I doubt there are four better pairings out of the entire forty-eight (twenty-four pairings in each book of The Well-Tempered Clavier).

Do they work, these string-quartet arrangements? Oh, yes. They make the preludes and fugues different (I think they are keyboard works, fundamentally). But Bach is still Bach. He is always Bach, no matter what you do to him. When the Swingle Singers sing him, he is Bach. When you bang him on a can, he remains Bach. He will always out, always.

I think The Well-Tempered Clavier is one of the most miraculous things ever to appear on earth—and that the hand that wrote them was scarcely human.