Chordindex
Play a chord. See the name.
Listens to whatever you're playing — a MIDI keyboard (USB or Bluetooth), the on-screen piano, or the on-screen fretboard — and names the chord live, in under a second. The name a musician would say in rehearsal, plus alternate names when they apply.
Features
Live Identification
Instantly names triads, sixths, sevenths, adds, extensions, altered chords, slash chords, and inversions. It provides alternate chord names, ranked for what a musician would actually call it.
Multi-View Sync
Every chord shows on three instruments at once: grand staff, piano, and guitar fretboard — always perfectly in sync.
Reverse Lookup
It's also a reverse dictionary. Look up a chord by name to see its tones, aliases, a piano voicing, a guitar diagram, and the staff — no instrument required.
Hardware Agnostic
Works with USB MIDI, Bluetooth MIDI, and other apps' virtual MIDI output. Don't have a MIDI keyboard? The on-screen piano and fretboard work standalone.
Practical Voicings
Includes a Rootless mode for practical left-hand voicings. Full sustain pedal support (MIDI CC64) means a held chord stays named after you release the keys.
Adaptive Interface
Enjoy a focused, stacked layout on iPhone, or a dedicated iPad teaching layout with staff, piano, and fretboard all visible together. Light and dark themes included.
Gallery
iPhone Layout
iPad & macOS Layout