A violin practice tool that listens to you play. Pick a scale, press Start, and Scaley follows you note by note, showing on the stave and on two meters exactly how sharp or flat you are.

How it plays

• It hears every note. The target note and the note you're playing sit side by side on the stave. A note only passes once you've held it in tune, so a scale can't be rushed.
• The meters show which way you're off. The left one fills when you're flat and the right one when you're sharp, so you know which way to move your finger.
• Four ways to practise: scales, arpeggios, random notes for sight-reading, and a string tuner.
• Letter names or solfège, and a built-in metronome.

How it's built

• Pitch detection runs in the browser, frame by frame, on the raw microphone signal. The browser's echo cancellation, noise suppression and auto-gain are switched off, because on phones they distort a sustained tone enough to make pitch detection jump around.
• Migrated from AngularJS to Next.js and shipped as a static export: no server at all, served from Cloudflare as an installable PWA.