Bach is the irreducible indispens­able of classical music. You would be hard pressed to find a performer who would admit to disliking him; and composers don’t use him — as Benjamin Britten used Beethoven and Brahms and Strauss, for example — to define a contrary aesthetic agenda. He is, as much as a dead white male can be, universal; and also, in a sense, pure. Concert pianists who spend a lot of their time with the Romantic longings which dominate the piano repertoire, from late Mozart to Rachmaninov, have been known to cleanse themselves with an icy immersion in the Bach keyboard works first thing in the morning.

In Bach there seems something morally uplifting: he was a supremely gifted artist, never to be surpassed, who founded an unbroken tradition in musical art, yet who was, as it were, unwittingly leading a day-to-day existence of surpassing ordinariness and, yes, decency. An assiduous, if prickly, municipal servant in Leipzig, he was a devoted father, married twice, to women who bore him 20 children between them: one in the eye for the supposed artistic imperative to excess and ­irresponsibility of a Lord Byron or a Jimi Hendrix.

Bach means “stream” in German — in his own era and area of Germany there were so many of the Bach family in music that it had also came to mean musician — and Bach’s pur­ity, like that of limpid water, is an easy contrast to draw with the worldly, commercially-minded, theatrical Handel, whose name is reminiscent of German words for shop and business.