Real MIDI Keyboard Support
Connect any MIDI keyboard over USB or Bluetooth. ChordFrog recognises chords in real time — including inversions and slash chords.
🎵 Ear Training — Reimagined
Train Your Ear. Master Chords. Leap Further.
ChordFrog is the iOS ear training app that grows with you — connect a MIDI keyboard for real-time chord recognition, or use quiz modes anywhere. Five progressive levels take you from simple triads to the full chord vocabulary.
Coming soon
See How It Works
✓ MIDI Keyboard Support ✓ Play Without a Piano ✓ 5 Progressive Levels
Everything you need to develop a real musical ear
Instant Ear Training
Hear target chords played with a premium piano sample library and train yourself to identify them by sound alone.
No Piano? No Problem.
Leap Quiz and Travel Chords modes work anywhere — on the bus, in a waiting room, whenever you have a few minutes.
Progressive Difficulty
Five levels from simple white-key triads up to the full set of major, minor, diminished, augmented, sus2 and sus4 chords.
Instant Feedback
Get real-time chord name display, wrong-answer correction, and automatic progression — so you stay in the zone.
Reference Playback
Every mode includes a "Play C" reference tone and chord replay so you always have a tonal anchor.
Four ways to practise
Whether your keyboard is plugged in or packed away, ChordFrog has a mode for the moment.
MIDI Required
Lily Pad Drill
Pick a level, listen to the mystery chord, then play it on your keyboard. Each correct answer advances you to the next challenge — no hand-holding, just progress.
MIDI Required
Free Pond
Just play. ChordFrog identifies every chord you play in real time and shows its name, inversion, and pitch classes — perfect for exploring and experimenting.
No MIDI Needed
Leap Quiz
Four options. One chord. Can you leap to the right answer? A multiple-choice format that sharpens your ear no matter where you are.
No MIDI Needed
Travel Chords
Tap any chord to hear it. Browse all practice-level chords at once — a handy audio reference you can reach for anytime.
Five levels. One deep pond.
Start with the basics and work your way down to the most challenging chord vocabulary.
1
The Shallows 7 white-key major triads
2
Still Water All 12 major triads
3
The Deep End Major + minor (24 chords)
4
The Rapids Major + minor + sus2 + sus4
5
The Abyss + diminished + augmented (full set)
1
The Shallows
7 white-key major triads
2
Still Water
All 12 major triads
3
The Deep End
Major + minor (24 chords)
4
The Rapids
Major + minor + sus2 + sus4
5
The Abyss
+ diminished + augmented (full set)
The Shallows
The Abyss
Built for musicians who take ear training seriously
Coming soon
Frequently asked questions
Do I need a MIDI keyboard to use ChordFrog?
No. ChordFrog has two modes that work without a keyboard: Leap Quiz (multiple-choice ear training) and Travel Chords (tap to hear any chord). For Lily Pad Drill and Free Pond, a MIDI keyboard is required for real-time chord recognition.
What MIDI keyboards are compatible?
ChordFrog works with any class-compliant USB MIDI keyboard when used with a suitable adapter (e.g. Lightning or USB-C). Bluetooth MIDI keyboards are also supported on compatible iOS devices, so you can connect wirelessly.
What chord types does ChordFrog recognise?
ChordFrog recognises major and minor triads, diminished and augmented triads, sus2 and sus4 chords, and slash chords (e.g. C/E). Inversions are displayed in real time in Free Pond and validated in Lily Pad Drill.
How are the practice levels structured?
Level 1 (The Shallows) uses seven white-key major triads. Level 2 adds all 12 major triads. Level 3 adds minor chords (24 total). Level 4 adds sus2 and sus4. Level 5 (The Abyss) includes diminished and augmented for the full set. You can practise any level in Lily Pad Drill or Leap Quiz.
Is ChordFrog suitable for beginners?
Yes. Start with Level 1 and Leap Quiz or Travel Chords to build familiarity. When you have access to a MIDI keyboard, Lily Pad Drill and Free Pond give instant feedback to reinforce recognition.
What device and iOS version do I need?
ChordFrog requires iOS 16 or later. It runs on iPhone and iPad. For MIDI, use a Lightning or USB-C adapter for USB MIDI, or a Bluetooth MIDI keyboard where supported.
Is ChordFrog free?
ChordFrog is free to download. Check the App Store listing for current pricing and any in-app offerings.
Ready to leap forward?
Download ChordFrog on the App Store and start training your ear today.
Coming soonRequires iOS 16 or later.