Ear Training

A tuner for chords — it names what you play and shows its function on a rotating wheel. The five surfaces at a glance, and how to read the wheel.

Each wedge on the wheel is a harmonic function in the key. How to read them — tonic, predominant, dominant — and what the colors and the lit wedge are telling you.

Home, Subdominant, Parallel, Relative, and Blues — the regions the wheel rotates between as music borrows and modulates. And the Lock button that holds it still.

How the wheel decides what key you're in: a live 12-bar confidence meter you can watch, commit, or override — and why locking a key is what lets the spaces rotate.

The on-screen keyboard shows a chord's notes with root and tones color-coded — and spells them the way a musician would, so E7's third is G♯, never A♭.

The small controls that decide what the wheel listens to and plays — the mic and speaker toggles — plus the bonus secondary-dominant wedges and the color legend.

Build and hear any scale from two four-note halves. Pick a lower and upper tetrachord, step through the modes, harmonize the tones, and browse the scale library.

Roll up a fresh diatonic progression, play it, and rotate its voicings — an idea spark that shows each chord as a function card so you learn while you browse.

The Musician Basics theory guide, built right into the app — so the wheel and the explanation of what it's showing you live in the same place.

The settings page — a tuning offset for sources that aren't at A=440, Camelot key codes for DJs, and Reset All. Everything here persists across launches.

A guide to the BKS Harmony Wheel — the real-time chord-to-function tool that names the chord you play and shows what it's doing in the key. Plus the Tetrachord Toolkit, Random Generator, and built-in guidebook.