Ballet class music, at your tempo
The Ballet Pianist is a free music player for dance classes. Play your own tracks and slow them down or speed them up live, from 65 % to 130 %, without changing the pitch.
What it does
- Live tempo change from 65 % to 130 % of the original speed, while the music plays, with the pitch unchanged. The time-stretching runs in real time in your browser, using the Rubber Band library.
- Your own music: MP3, M4A / AAC, WAV, FLAC and Ogg files. Add files, or a whole folder on a computer.
- A library in your browser: search, continuous play, repeat, and a start delay (3 to 30 seconds) so you can get into position before the music starts.
- Volume and clarity: a treble tone control to make the sound rounder or brighter, depending on the speakers.
- On every device: phones, tablets and computers, right in the browser. It can be installed like an app, works offline after your first visits, and on Android it keeps playing with the screen off.
Getting started
- Open the player and add your music with “Add files…”.
- Tap a track in the library: it starts playing. Tap it again to pause.
- Set the tempo with the big slider. You hear the change right away.
The tempo is remembered for each track, so next time it starts at the same speed.
Install it like an app
- iPhone / iPad (Safari): tap Share, then “Add to Home Screen”.
- Android (Chrome): tap the ⋮ menu, then “Install app” or “Add to Home screen”.
- Mac (Safari): File menu, then “Add to Dock”.
- Chrome or Edge (computer): use the “Install” icon on the right of the address bar.
The user guide has the detailed steps.
Why 65 % to 130 %?
The range is a quality choice, not a technical limit. Time-stretching can go further, but beyond this range the sound clearly degrades. We preferred to offer only settings that sound good.
Frequently asked questions
Is it really free?
Yes. The Ballet Pianist is free and open source (GPL), with no ads. If it is useful to you, a voluntary donation is possible, but it is never required.
Do I need an account, and is my music uploaded?
There is no account and no cookies. Your music never leaves your device: it is copied into your browser's own storage, and nothing is sent over the Internet.
Does changing the tempo change the pitch?
No, the pitch is preserved. Beyond about ±20 to 30 %, a solo instrument such as a piano may sound slightly different: this is true of all software of this kind.
Which devices and browsers work?
Safari, Chrome, Firefox and Edge on computers, Safari on iPhone and iPad, and Chrome on Android.
Can I use WMA files?
No web browser can play WMA, so convert those files to MP3 first. Files protected by DRM cannot be played either. The user guide explains how.
Support the project
If The Ballet Pianist helps your classes, you can support the project with a voluntary donation. Everyone gives what they wish, or nothing at all.