This is one of the truly immortal melodies in human history, and one of a surprisingly small handful of straightforward melodic highlights in Bach’s work. It was originally the closing section to one of Bach’s cantatas, Herz und Mund und Tat und Leben, which wound up becoming perhaps the most famous of his cantatas after Wachet Auf primarily because of producing this perennial Classical-music chestnut. In reality, Bach was a melodist equal to Mozart and Schubert and possibly even greater, even if, for all his acclaim, he is rarely given credit for that aspect of his work. All his melodies are probably this good—it’s just that because he was the master of old-school Polyphony, there’s nearly always three or more of them playing at the same time. This means that however glorious the overall whole sounds, discerning and absorbing the individual melodies is extraordinarily difficult. Indeed, even an expert would probably have trouble with that because the sheer sensory overload of celestial beauty in Bach’s music makes it surprisingly hard to listen to analytically. Bach’s music is basically like looking into the sun…its beauty is so intense as to be blinding. Even this comparatively simple solo tune can be overwhelming in the sheer exquisite purity of its rising and falling melody…yes, even when reduced to the standard instrumental snippet form in which it is most often heard these days.