No install · Web Audio · open source

Strum your
keyboard.

A new instrument. Four rows, six chords.Sweep a column — hear it ring.

Start playing →See the mapping
↓ Just press any key below
press any key to start
row 1 → E4 · row 2 → B3 · row 3 → G3 · row 4 → D3try: 1-q-a-z (Am) · 5-t-g-b (Dm) · 6-y-h-n (F) fast ↓↑· cols 7+ (7-= · u-] · j-' · m-/): palm-muted ghost notes
Built formusic beginners·DAW producers·late-night jammers·music teachers
Features

An instrument that fits in your keyboard.

4×

Four-row mapping

Number row to Z row — each physical row is a string. Each vertical column is a chord. The layout clicks the moment you try it.

⚡

Strum detection

Sweep a column top-down in under 90ms and keystrum reads it as a downstroke. Reverse for upstroke. It feels physical.

◉

Zero install

Karplus-Strong synthesis in the browser. No samples, no plugins, no account. This instrument lives in your tab.

How it works

Four rows. Six chords. One sweep.

01

Find the rows

Numbers, QWERTY, ASDF, ZXCV. Four rows, four strings. Top row is the highest pitch.

02

Pick a column

Each vertical column is a chord: 1qaz = Am, 2wsx = C, 3edc = Em, 4rfv = G, 5tgb = Dm, 6yhn = F.

03

Sweep it

Hit two or more keys in a column — fast, top to bottom. That sweep is a strum. The faster you go, the tighter it sounds.

New · Practice mode

Learn the instrument with songs.

A character shows you when to strum, hold, and mute. Three folk songs, six chord lanes, timing windows of 60/120/200 ms.

Start practicing→
Reference · Chord dictionary

Six chords, six columns.

Am · C · Em · G · Dm · F. Each chord's notes, intervals, keyboard mapping, and the songs that made it famous.

Open dictionary→
“No testimonials yet.
Try it — yours might go here.”
— the honesty policy

Quick answers

Does it work on mobile?
The page loads, but strumming needs a physical keyboard. On-screen keys work as a fallback. Practice mode has touch support.
Is there a practice mode?
Yes — /play has three songs where a character shows you when to strum, hold, and mute. Scores save locally and can be shared via URL.
Why four strings?
QWERTY has four rows. keystrum uses all four — that's the instrument's design, not a limitation.
Can I change the chords?
Not yet on v1. Column presets will be editable in the next release. Six chords available now: Am, C, Em, G, Dm, F.
What makes the sound?
Karplus-Strong synthesis — a physical modeling algorithm running in Web Audio. No samples, no downloads. The sound is generated live in your browser.

Stop reading. Strum.

Scroll back up. Hit 2, w, s, x — one after the other, fast.

↑ Back to the instrument