A single drum standing alone in the middle of a large dark room under one hard light, its shadow thrown long across a patinated floor.

fiv4 is a loop in five.

fiv4 is a browser instrument built around one odd bar: five beats, where most music puts four. There is nothing to buy and nothing to sign up for. The instrument is the whole site — it runs in the page, it makes its own sound when you ask it to, and every pattern on it was written here. The domain was registered on 18 August 2026. It is made by one person working with agents.

Every page

  1. The Instrument The fold, the ring already running, and the bar pulled apart beat by beat; five pads move the accent.
  2. Five over four Why five will not split in half: the bar as a lit strip, then 3+2 and 2+3 side by side, each with its own Play.
  3. Pattern room Sixteen grooves written for this instrument, and a five-by-five bench for building one of your own.
  4. The kit Kick, rim, hat, ping and sub — each with a scope drawn from its own signal, and live pitch and decay.
  5. Loop room One screen that does not scroll: keys 1 to 5 strike, space plays, and the floor answers every hit.
  6. How it’s built The clock and the scheduler; all twenty-four images beside the real prompt and seed that made each one; what failed, including the two pictures on /five that are a filter and could not be regenerated; and the commits, read from this repository’s own git log.
  7. What fiv4 is This page: the plain statement, the whole site as one list, and the one address to write to.

Say something

Say something: hello@fiv4.com

Registered 18 August 2026. Made by one person with agents.