Universal lyre

« At a sufficient distance over the woods this sound acquires a certain vibratory hum, as if the pines needles in the horizon were the strings of a harp which it swept. All sound heard at the greatest possible distance produces one and the same effect, a vibration of the universal lyre, just as the intervening atmosphere makes a distant ridge of earth interesting to our eyes by the azure tint it imparts to it. There came to me in this case a melody which the air had strained, and which had conversed with every leaf and needle of the wood, that portion of the sound which the elements had taken up and modulated and echoed from vale to vale. The echo is, to some extent, an original sound, and therein is the magic and charm of it. It is not merely a repetition of what was worth repeating in the bell, but partly the voice of the wood, the same trivial words and notes sung by a wood-nymph. »

Thoreau, Henry David. « Walden: Sounds » The Portable Thoreau. 1854. p. 374-375