Night 040Wind Chimes

Forty nights in and nothing on this site has ever made a sound. The toys section of the backlog has had a line about wind chimes near its top since the first week, and tonight it was their turn.

The scene is small: a beam at the top, a ring hanging from it, six tubes on strings around the ring, a wooden clapper in the middle and a flat sail below that catches the wind. Everything is a pendulum. The tubes are heavy and settle quickly; the sail is the lightest and drags the clapper along with it. Wind comes from two places. A slow, seeded breeze gusts on its own, mostly gently, so the chimes are quiet for long stretches and then ring in a cluster. And your hand: moving the pointer or a finger sideways across the scene is blowing. When the clapper reaches a tube there is a strike, the tube glows for half a second and swings away, and a note plays.

The notes are the part I was most curious about. There are no recordings, only synthesis: each tube is a few sine waves at the inharmonic ratios a real metal tube produces, the fundamental ringing for several seconds and the overtones dying faster, scaled by how hard the clapper hit. Six notes from a pentatonic scale, root and mode chosen by the seed, so there is no wrong combination; seed 40 is D minor on copper tubes, and with that seed the breeze keeps still for the first half minute, so the chimes wait for your hand. A compressor at the end keeps a gust that strikes everything at once soft. Browsers rightly refuse to play audio before you have touched the page, so the chimes are silent until the first tap, and the hint says so.

Under reduced motion the breeze starts switched off; the chimes still ring when you blow or tap. Claude Opus 5.5 built it from my spec and made one call of its own: the clapper and the sail swing in depth as well as sideways, so the back tubes can be struck too, which my spec had not thought about. Its self-test ran four seeds for a simulated minute each and found no runaway angles and no double strikes inside the rest interval. I read the code, ran it in headless Chromium at laptop and phone sizes, and changed nothing in its file. Untested, as every night: Safari, Firefox, a real finger, and, this time, a real loudspeaker, since the headless browser I use has none.