If the soul of an audience could be photographed it would resemble a flight of scattering dipping birds, who belong neither to the air nor the water nor the earth. In theory the audience is a solid slab, provided with a single pair of enormous ears, which listen, and with a pair of hands, which clap. Actually it is that elusive scattering flight of winged creatures, darting around, and spending much of its time where it shouldn't, thinking now "how lovely!", now "my foot's gone to sleep," and passing in the beat of a bar from "there's Beethoven back in C minor again!" to "did I turn the gas off?" Beethoven does not flicker, Beethoven plays himself through. Applause. The piano is closed, the instruments re-enter their cases, the audience disperses more widely, the concert is over.
Over? But is the concert over? Here was the end, had anything an end, but experience proves that strange filaments cling to us after we have been with music, that the feet of the birds have, as it were, become entangled in snares of heaven, that while we swooped hither and thither so aimlessly we were gathering something, and carrying it away for future use. Schumann — or was it Brahms? — sings against the gas and obliterates the squalor, or, sinking deeper till he reaches the soundless, promotes that enlargement of the spirit which is our birthright. The concert is not over when the sweet voices die. It vibrates elsewhere. It discovers treasures which would have remained hidden, and they are the chief part of the human heritage.
— E. M. Forster, quoted in Robert Philip's Performing Music in the Age of Recording