Plucked Strings

Karplus–Strong: fill a delay line with pure noise and a guitar comes out.

audio.pluck · v1 · renderer audio

0:00 / 0:00

Karplus–Strong · Minor pentatonic (blues) on A3 · 38 notes over 8 bars at 92 BPM · sustain 0.55 · spread 0.70

Every note starts as a delay line full of white noise. The length of the line picks the pitch out of it, and a two-point average takes the brightness off a little more on each lap — which is what a real string does.

[data-audio-stage] { display: none; }

Synthesised in the browser

No audio file crosses the wire. The server sends a score — the events, envelopes and synthesis parameters below, plus a 32-byte key — and the samples are made here, from the same byte stream the server would have used. A four-minute piece is about two kilobytes of JSON. That needs JavaScript, so with it switched off there is nothing to play.

The score itself is still public: /api/v1/g/audio.pluck returns it, and the synthesis is in resources/js/audio.

Karplus–Strong · Minor pentatonic (blues) on A3 · 38 notes over 8 bars at 92 BPM · sustain 0.55 · spread 0.70

entropy in

16 bytes

stream used

1,076 bytes

rejections

duration

421 µs

scale

Minor pentatonic (blues) on A3

notes

decay per lap

0.99

pitch span

A3 – A5

duration

24.9 s

Seed receipt

Class B · Public beacon cached

NIST Beacon pulse #1,939,957 — chained to every pulse before it, and signed.

Published openly — anyone can look this value up after the fact.

source: NIST Randomness Beacon
observed: 2026-09-13T18:43:00+00:00
latency: 0ms
mixed with: csprng — always

https://beacon.nist.gov/beacon/2.0/chain/2/pulse/1939957 ↗

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The token is the seed, so this link recomputes the result rather than looking it up. No database, and it works for as long as v1 does.

Controls · from schema()

Scale

Root

Octave

1 5

Range (octaves)

1 3

Notes per bar

1 12

Bars

1 16

Tempo (BPM)

50 180

Sustain

0 1

How much of the loop survives each lap. Past about 0.9 the string stops being a string and becomes a drone.

Brightness

0 1

Where the string is plucked. Near the bridge is bright and thin; over the fretboard is round and dark.

Stereo spread

0 1

How far across the image the notes are placed. Strings recorded close are never all in the same spot.

Double stops

0 0.6

How often two strings are struck at once.

Volume (dBFS)

-36 0

Where the mix sits before the master limiter. 0 dBFS is full scale; everything starts 12 dB below it.

Entropy source

Picking a source changes the story on the receipt, never the quality: anything below class A is mixed with the OS CSPRNG before it reaches you. This result actually came from NIST Randomness Beacon.

seed token 18S08JP24CKQQB06S5JQ6SJV00

Re-render keeps this token. Generate replaces it. That is the whole idea.

The file is the render, sample for sample — not a second performance of it. The seed below reproduces it anywhere.

monitor

80%

This page and /api/v1/g/audio.pluck run the same code. There is no private endpoint.

Plucked Strings

Result

Measurements

Seed receipt

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