I once met a boy at a house party who could do the most beautiful thing. A small gesture, an insignificant addition to the moment, but precise and resonant. By the end of the last Gilmour solo in "Dogs," right after a simple melody of high tones, this boy, this taciturn, mellow, sweet boy, would give the slightest of whistles. A downscale five-tone tune that lasted two seconds. He would do nothing more after this and would stay quiet in his chair, apparently enjoying the conversation.