You may be sitting in a room reading a book. Imagine one note struck on the piano. Immediately that one note is enough to change the atmosphere of the room--proving that the sound element in music is a powerful and mysterious agent, which it would be foolish to deride or belittle.The experience he mentions is instantly recognizable to almost everyone. There are certain pieces of music that can alter my mood in just a few seconds, but this effect is not exclusive to music. It can happen while reading certain authors as well. I don't mean the effect created by a novel's plot or its descriptive atmospherics. It is more the sound quality of certain writers, their tone and language. I remember years ago reading Ulysses for the first time and having an alternately maddening and fascinating time of it. I had to use Stuart Gilbert’s outline to claw my way through, but I still found it an astonishing novel. My eye would forage along a line of Joyce gobbling up entire meals of words and phrases. It's a novel read as much on the tongue as with the eye.
Indeed, reading Ulysses was like having a language factory humming along on in my head. I had the desire to spew obscure words and long serpentine sentences. Only Shakespeare can give me the language flu like that. Tolstoy (in translation, of course) can create a certain flavor in my mind, a certain distinct feeling in my gut. Homer does this as well. Read enough of Homer and I can practically smell the cattle thighs roasting over open fires, but only Joyce and Shakespeare give me the hunger to let the taste of English spill over my tongue.