About ChordFrog

ChordFrog was built by a musician and developer who wanted a better way to practise chord recognition with a real keyboard. The idea started simply: plug in a MIDI keyboard, hear a chord, play it back, get instant feedback. No accounts, no subscriptions, no bloat — just a focused tool that does one thing well.

Existing ear training apps fell into two camps. Some were passive — multiple choice only, no keyboard, no physical engagement. Others were sprawling music theory suites that tried to teach everything from intervals to counterpoint. The gap in between was a dedicated chord recognition trainer that actually uses your MIDI keyboard for hands-on practice while also working as a standalone listening tool when you're away from the piano.

The frog theme emerged naturally. Frogs are known for their excellent hearing — they rely on it to communicate, find mates, and sense their environment. The level names (The Campfire, The Session, The Gig, The Studio, The Abyss) describe the path of a real musician — from the classics everyone knows to the full harmonic vocabulary. It felt right.

The piano sound matters for ear training. Synthetic tones and simple waveforms don't train your ear for real music. ChordFrog uses the Salamander Grand Piano sample library — a careful recording of a real Yamaha C5 grand piano, released under Creative Commons BY 3.0. When you practise with ChordFrog, you're hearing chords as they sound on an actual instrument.

ChordFrog is built independently in Finland. No venture capital, no growth team, no tracking pixels. Just an app that helps musicians hear better.

ChordFrog covers all six triad types and is adding seventh chords — dominant 7th, major 7th, and minor 7th — to the ear training levels. The foundation always comes first.