ChordBeam uses the Web MIDI API — a browser technology that connects directly to your keyboard over USB. No drivers, no plugins, no latency. Here is exactly how to get it running.
Open Chord DetectorUse the USB Type-B port on your keyboard (the square-ish one) and connect it to a USB-A or USB-C port on your computer. Most modern keyboards are class-compliant, meaning no driver installation is required — the OS recognises them immediately.
The Web MIDI API is fully supported in Chromium-based browsers. Open ChordBeam, then navigate to the Chord Detector. You will see a MIDI status indicator near the top of the detector panel.
On your first visit, Chrome will ask for permission to access your MIDI devices. Click Allow. If you accidentally denied it, go to Settings → Site settings → MIDI and reset the permission for chordbeam.app.
Once MIDI access is granted, your keyboard will appear in the device selector. Select it. The indicator will turn green and the detector will start responding to your playing immediately.
Play any notes or chords on your keyboard. ChordBeam identifies the chord name, displays the notes, and shows harmonic context on the theory wheel — all in real time with no latency.
The Yamaha MODX and MODX+ series support USB MIDI natively and work with ChordBeam without any additional setup. Connect via the USB-B port on the rear panel. In the MODX Utility menu, make sure USB MIDI is set to MIDI (not Audio/MIDI). Chrome will detect the MODX8+ as "Yamaha MODX8+" or similar — select it in ChordBeam's device dropdown and you are ready to play.
If you use the Expanded Softsynth Plugin (MODX+) and have multiple USB audio/MIDI interfaces active, ensure you select the correct MIDI input — the MODX may appear more than once if the driver enumerates both ports.
Web MIDI is a browser-level API. Support varies — Chromium-based browsers have the best coverage.
Check that your keyboard is powered on and the USB cable is firmly connected. Try a different USB port. On Windows, check Device Manager to confirm the keyboard is recognized by the OS.
Click the padlock icon in Chrome's address bar → Reset permissions, then reload the page. Alternatively go to chrome://settings/content/midi and remove the blocked entry for chordbeam.app.
Confirm the correct input device is selected in the MIDI device dropdown. Some keyboards have a "Local Control" or "MIDI Out" setting that needs to be enabled in the keyboard's system settings.
Make sure you are playing all chord notes simultaneously and holding them. ChordBeam analyses active notes — partial voicings or fast arpeggios may produce unexpected results.
Firefox does not natively support the Web MIDI API. Install the Jazz-Plugin browser extension or switch to Chrome or Edge for the best experience.
Once your keyboard is connected, open the live detector and start playing. ChordBeam shows you the chord name, note spelling, and harmonic context instantly.
