Music drawn from memory, he writes, “has many of the same effects as real music coming from the external world.”

Listening to music is not just auditory and emotional, it is motoric as well: “We listen to music with our muscles,” as Nietzsche wrote. We keep time to music,

Perhaps it is not just the nervous system, but music itself that has something very peculiar about it—its beat, its melodic contours, so different from those of speech, and its peculiarly direct connection to the emotions.

I tend to fall in love with a certain composer or artist and to play their music over and over, almost exclusively, for weeks or months, until it is replaced with something else.

But for virtually all of us, music has great power, whether or not we seek it out or think of ourselves as particularly “musical.”

“It alleviates boredom, makes…movements more rhythmical, and reduces fatigue.” It buoys the spirits,

Half of us are plugged into iPods, immersed in daylong concerts of our own choosing, virtually oblivious to the environment—and for those who are not plugged in, there is nonstop music, unavoidable and often of deafening intensity, in restaurants, bars, shops, and gyms. This barrage of music puts a certain strain on our exquisitely sensitive

“The inexpressible depth of music,” Schopenhauer wrote, “so easy to understand and yet so inexplicable, is due to the fact that it reproduces all the emotions of our innermost being, but entirely without reality and remote from its pain…. Music expresses only the quintessence of life and of its events, never these themselves.”

We are on much richer, much more mysterious terrain when we consider tunes or musical fragments we have perhaps not heard or thought of in decades, that suddenly play in the mind for no apparent reason.