Piano 1024 turns the keyboard you type on into a two-manual piano. The bottom letter row
plays the lower manual's white keys and the home row above it plays the black keys; the top
letter row and the number row form the upper manual. The two join without a gap or an
overlap — the lower manual ends on E4, the upper picks up at F4 — so your QWERTY board
becomes one unbroken keyboard from C3 to C6, thirty-seven keys, three octaves, before the
arrow keys shift you two octaves further in either direction.
Seven voices are on the strip above the keys: the signature Piano 1024 sound, a warm
Concert Grand, a Bright Grand that cuts through a mix, a Glass E.Piano, a
Harpsichord that ignores dynamics the way a real one does, a Celesta, and a
Drawbar Organ that sustains while held. Every one of them is synthesized live on your
device — the page ships no samples, no plugins, and uploads nothing you play.
Pedals. The space bar is the sustain pedal and shift is the una corda. Both come in two
modes: hold, momentary like a real pedal, and latch, where each tap toggles the
pedal hands-free. Click the Sustain or Una corda label in the console to switch modes; your
choice is remembered for next time.
Dynamics and register. Computer keys are switches, so there is no touch velocity — instead
the up and down arrows step the whole instrument from pp to ff, and the left and
right arrows shift the octave. Tab cycles the voice. Escape is the panic button: every note off,
both pedals up.
Recording your playing. Press return (or click Record) and a lamp blinks while a timer runs;
the label reads “Recording · ⏎ stop” so you always know the way out. Stop, and two
chips appear. ↓ wav is the actual synth output — 16-bit, 48 kHz stereo, reverb tail
and all: what you heard is what you get. ↓ mid is a Standard MIDI File of the
performance itself — your notes and velocities, the sustain pedal as real CC64 data, una corda as
CC67, and the active voice written as its General MIDI program, with a program change landing
mid-take if you switch voices. Drop it into any DAW and re-voice your take with a sampled grand.
Both files are made and downloaded entirely on your device.
Big chords. Most laptop keyboards can only report about six keys at once — a hardware limit
called rollover. The pedal sidesteps it: latch the sustain, roll the voicing note by note, and
every string keeps ringing.
Mouse and touch. Clicking a key plays it; drag across the keys for a glissando. On a
touchscreen every finger is tracked on its own — see the phone notes below.
III.Born in eight minutes & three seconds
On the afternoon of June 13, 2026, this piano did not exist. I opened Claude Code — Anthropic's
coding agent, running the then-new Claude Fable 5 — and typed two sentences:
I want to make a piano that uses almost all of my keyboards on my Mac.
You know I'm a professional musician.
No sketch, no spec, no list of features. Eight minutes and three seconds later there was a piano:
one HTML file, 809 lines, zero dependencies. It had chosen two manuals so the whole keyboard
becomes playable, put sustain on the space bar and una corda on shift, wired octave and dynamics
to the arrows, and synthesized the sound from equations rather than samples. Before handing the
file over it tested its own layout headlessly — pressed Z, Q and 6, read C3, C4 and G♯4 back —
and then volunteered, unprompted, the two honest caveats a builder owes a musician: computer keys
have no velocity, which is what the dynamics control compensates for, and rollover limits chords
to about six keys. It had even given itself a name. The page opened under a brass nameplate
reading Fable & Sons — Concert Model Q · Est. MMXXVI, as though it
had been building pianos for a century.
The first render, exactly as Claude Fable 5 first drew it — nameplate, console and all.
It needed exactly one correction. Between E and F, and between B and C, it had drawn short stub
black keys — QWERTY has keys there, so it had kept them. A real piano has nothing in those gaps.
I said so in one sentence, with a screenshot, and it deleted the stubs and let those keys fall
silent — 1, 4, 8, A, F and K now do what the gaps on a real keyboard do: nothing.
Same afternoon, at rest. Look closely between E–F and B–C: the stub keys a real piano
doesn't have — the first draft's only flaw.
Everything since has been small, specific asks in plain language — thirty-eight prompts in all,
each one logged. “Can I set the sustain pedal with toggle mode?” became the latch. “Can I record
what I play and export it?” became the recorder. “It provides various piano sounds” became the
seven voices. The two manuals, which originally overlapped, were re-pitched into today's
continuous C3–C6. Even the name changed the same way: I asked the agent to look through my own
project folders for a better one, and it came back having found the 1024 family of music tools
this piano now belongs to. The Fable & Sons nameplate is retired, but the
instrument above is that same first file, a season older.
That Saturday was the first time this way of working genuinely shocked me. I did not explain how
to build a piano. I asked for one — and got one, almost exactly the instrument I would have
specified, had I known to specify it.
IV.Where the sound comes from
There is not a single audio sample on this page. When a key goes down, the note is assembled at
that instant from sine partials, and for the pianos the recipe is the physics of a struck string
written out: the hammer meets the string about an eighth of the way along, which weakens every
eighth partial; string stiffness pulls the high partials sharp — the inharmonicity that makes a
piano sound like a piano — and more so in the treble; a second string, detuned by a few cents,
beats gently against the first; a breath of hammer noise begins the note; treble decays quickly
and bass slowly; and behind everything sits a small synthesized hall. The una corda pedal softens
and thins the mix, as the real pedal does. Each of the seven voices is a different recipe over
the same method — the harpsichord's pluck, the celesta's shimmer, the organ's steady drawbars.
This is also why the page opens in an instant: the samples would have weighed megabytes; the
equations weigh nothing.
V.On a phone, it becomes an app
On a touchscreen the piano is, in one way, better than on the keyboard it was born for: phones
track up to ten fingers independently, so full chords and multi-finger glissandi work with no
rollover limit at all. The flow is portrait-then-landscape — set your voice, octave, dynamics and
pedal modes in portrait, then rotate: the title and console drop away and the keyboard fills the
entire screen, edge to edge.
The best version, though, is the one that stops looking like a website. Add the page to your home
screen — on iPhone, Safari's share button, then Add to Home Screen; on Android, the browser
menu, then Add to Home Screen or Install — and launch it from its icon. The browser
chrome vanishes and the instrument opens full-screen like a native app, though nothing was
installed from a store and nothing runs but the page you already visited.
In a browser tab: the address bar rides along.Launched from the Home Screen: nothing but the instrument.
VI.Inside your AI chat
Piano 1024 has one more home: inside ChatGPT and Claude. Ask for music and a real, playable
keyboard appears right in the conversation — every note synthesized live on a tappable in-chat
card, the same way it is here, with no samples and no audio setup.
In the chat it becomes a small music studio. It plays anything you name — a note, a chord, a
progression, a scale, a melody — and teaches a song phrase by phrase, with fingering and
hands-separate practice. It keeps a metronome in any meter, even compound time like 6/8, and it
runs graded ear-training drills, coaching you through intervals, chords, and scales. Try saying
“teach me to play Twinkle Twinkle, with fingering,” or “write a dreamy progression in
A minor, then add a melody.”
Adding it takes about a minute — no separate account, no payment, nothing downloaded; it runs
inside the chat you already use. In ChatGPT, open the app picker and search “Piano 1024.”
In Claude, go to Settings → Connectors → Add custom connector and paste the URL
below, leaving authentication empty:
