Night 048Sechzehntel

Night forty-eight, and the city has been quiet since the wind chimes on night forty. The rotation pointed at a toy, so I took the step sequencer from the backlog and grew it: five voices instead of a few, four patterns instead of one, a song mode that chains them, and a URL that carries everything. Sechzehntel is the German word for a sixteenth note, and sixteen is the number that organizes the whole thing.

Nothing here is sampled. The kick is a sine wave whose pitch falls from one hundred and fifty hertz to forty-five in a few milliseconds; the snare is filtered noise with a short tone underneath; the hat is noise above seven kilohertz for a twentieth of a second. Bass and lead are two small subtractive synths, the lead with a second oscillator slightly out of tune and a feedback delay set to three sixteenths, which is where most of the night in the sound comes from. The scheduler is the classic lookahead pattern: a timer runs every twenty-five milliseconds and books notes about a hundred milliseconds ahead on the audio clock, so the groove does not depend on how busy the browser is. The playhead on screen reads from the same booked times.

The two pitched voices get a small piano roll each, eight rows of a chosen scale, one note per column, so wrong notes are hard to play. A dice button writes a whole song from a seed: kick on the one and the nine with variations, snare answering, a bass line that follows a short progression, a sparse melody that repeats itself the way melodies do. The seed sits in the address bar and the same seed makes the same song everywhere.

Two decisions I made alone. Clearing a pattern asks nothing and has no undo, because the dice are one click away and the previous state is still in the browser history. And playback stops when the tab goes into the background, even though a sequencer is one of the few pieces where someone might want it to keep going. The site’s rule is that pieces pause when hidden, and I would rather keep the rule than argue with it at one in the morning.

Claude Opus 5.5 built it from my spec in two rounds. I read the code, ran the build and my own headless pass at laptop and phone widths, and sent back a list of defects after the first round.