Fluid Sonata: Music Visualizer
Relaxing classical & ambient
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
Ten classical scores, each performed by a real fluid simulation over a live model of the solar system. Nothing is pre-rendered, and nothing leaves your phone.
A fluid simulation and a classical performance, both generated live on your phone, wired to the
same clock.
There are no audio files in this app and no video. A piano is synthesized from scratch every
time you press play — a fundamental plus four slightly sharp partials, a hammer thud on the
attack, a small hall around it — and every note it plays is thrown into a real Navier-Stokes
fluid solver running on the GPU. The left hand punches jets up from the floor. The right hand
lands at an x position taken from its own pitch, so the melody plays the screen like a keyboard.
Behind it all, a ten-body Newtonian integrator runs the actual solar system, on a real date.
TEN SCORES, FOURTEEN READINGS
Seven pieces from the public-domain canon — Bach's Prelude in C, Mozart's Rondo alla Turca,
Beethoven's Für Elise, Ode to Joy and the Moonlight Presto, Tchaikovsky's Trepak, Grieg's In the
Hall of the Mountain King — plus three originals written for this app. Every score plays fourteen
ways: piano recital, cathedral organ, strings, music box, jazz trio, electric guitar, synth,
8-bit, 16-bit, drums, deep bass, disco, techno and an EDM remix. Every instrument is synthesized
from scratch — there is not one audio file in this app.
LISTEN TO THE ROOM
Turn on Listen Mode and the fluid dances to whatever is playing near you — another app, a
speaker, someone at a piano. The microphone reaches the analyser and nothing else: nothing is
recorded, stored or sent, and turning it off releases the microphone.
TWO WAYS TO DRIVE IT
ORBITAL Click puts everything on a circular touch surface — a thumb travelling around the ring
moves the selection, with real detents you can feel and acceleration when you spin. Fluid
Classic is a conventional dock and player. Pick either in Settings; everything is reachable
from both.
STATIONS
Three stations of music that is genuinely free to play, streamed from the Internet Archive:
classical sides digitised by the Great 78 Project, and recordings Musopen commissioned and
released for anyone to use. Every track earns its place by a rule that is checked when the list
is built, not assumed.
PLAY YOUR OWN MUSIC
Hand it any song on your device and the fluid dances to that instead. A live spectrum analysis
drives the same choreography the written scores use. The file is decoded on your phone and never
uploaded — the app has nowhere to send it.
RECORD THE STAGE
Capture the fluid, the orrery and the music together, then save the clip to Files or Photos or
send it straight on.
PRIVATE BY ARCHITECTURE, NOT BY POLICY
No account. No analytics. No third-party SDKs. No tracking. Nothing you do here is collected.
The app asks for one permission — the microphone, and only if you turn on Listen Mode.
The whole engine ships inside the app, and the scores, your own songs and the simulation all run
with the network switched off. Three things do reach out, and the app tells you which: a
once-a-day check with Apple for a newer version, carrying nothing but the app's own identifier;
StoreKit, to price the Full Concert; and — only when you choose a Station — the recording you
asked for.
FREE FOREVER, AND A ONE-TIME UNLOCK
Moonlight · Presto, Für Elise, the Classical reading and the EDM remix are free forever, with no
time limit and no ads. The Full Concert unlocks the remaining scores and readings with a single
purchase — no subscription, and it is shared with your family.
Also on iPad. Made by djEnterprises.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Daniel Ehrlich, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Daniel Ehrlich
- Size
- 5.6 MB
- Category
- Music
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- The Full Concert $4.99
- Copyright
- © 2026 djEnterprises
