Light-Up Piano

A browser replacement for the POP Piano app: play MIDI files on your lighted-key piano and learn songs one segment at a time.

not connected Keys

Song

Open .mid… no file loaded

Speed 100% Volume sound on this computer sound on the piano

0:00 / 0:00

Click a key to turn its light on or off (in Learn mode a click counts as playing it). ■ lit · ■ you're pressing it.

This page replaces the POP Piano app for pianos with light-up keys. It runs entirely in your browser and talks to the piano over Bluetooth.

Tested with a Vangoa 88-key lighted piano. It should also work with other light-up keyboards built on the same Bluetooth module, the ones that work with POP Piano.
Look for a Bluetooth device named GZUT-MIDI when you connect. The connect dialog only lists devices whose name starts with "GZUT" or that offer Bluetooth MIDI.
Use desktop Chrome or Edge. The page needs Web Bluetooth, which Safari and Firefox don't support.
The piano accepts one connection at a time. Close POP Piano on your phone and don't pair the piano in your computer's MIDI settings (Audio MIDI Setup on a Mac) before connecting here.
Regular MIDI apps can't drive the lights. The piano's firmware only accepts Bluetooth MIDI packets with a fixed timestamp, and the operating system's MIDI stack (including Web MIDI) always sends real timestamps. That's why this page talks to Bluetooth directly.

Protocol notes (for developers)

Standard BLE MIDI: service 03b80e5a-ede8-4b33-a751-6ce34ec4c700, characteristic 7772e5db-3868-4112-a1a9-f2669d106bf3. Write without response; subscribe to notifications to receive the keys you press.
Every packet must use the timestamp bytes 80 80.
Light a key: 80 80 F0 4D 4C 4E 45 <note> 02 80 F7 (the bytes 4D 4C 4E 45 are "MLNE" in ASCII). Send 00 instead of 02 to turn it off.
All lights off: 80 80 F0 50 00 00 00 00 00 80 F7
Play a sound: 80 80 90 <note> <velocity> (and 80 80 80 <note> 00 to release). Several notes can go in one packet, each preceded by 80. Notes sent this way don't light their keys.
No initialization or handshake is needed.

Not affiliated with Vangoa or POP Piano. The protocol was worked out by capturing the Bluetooth traffic between the POP Piano app and the piano.