How chords are named
A chord is three or more notes played together. Its name comes from two things: the root (the note it is built on) and the quality (the pattern of intervals above the root). Stack a major third and a perfect fifth on C and you get C major. Swap the major third for a minor third and you get C minor.
Chord formulas
| Chord | Formula | Example on C |
|---|---|---|
| Major | 1 3 5 | C E G |
| Minor | 1 ♭3 5 | C E♭ G |
| Diminished | 1 ♭3 ♭5 | C E♭ G♭ |
| Augmented | 1 3 ♯5 | C E G♯ |
| Dominant 7th | 1 3 5 ♭7 | C E G B♭ |
| Major 7th | 1 3 5 7 | C E G B |
| Minor 7th | 1 ♭3 5 ♭7 | C E♭ G B♭ |
| Suspended 4th | 1 4 5 | C F G |
Inversions and slash chords
When a chord tone other than the root is the lowest note, the chord is inverted. C E G with E at the bottom is the first inversion of C major, written C/E. The notes are the same, only the bass changes, so slash chords are a way of writing which note sits at the bottom.
Why can one set of notes have two names?
A chord's name depends on which note you hear as home. The notes A C E G are Am7 if A is the root, and C6 if C is the root. Context decides: the chords around it, the bass note and where the music is heading. Telling the finder the lowest note usually settles it.
How to use the finder
- Tap the notes you are playing. Selected keys light up and show their names.
- Choose sharps or flats for how black keys are spelled.
- If you know the bass note, pick it under "Lowest note".
- Read off the chord name, its notes, and other possible names.
Once you know a chord, see how to play it on guitar or ukulele, put it in a song with the transposer, or find its key with the chords to key finder. Want to practise? Try the piano key trainer.
Frequently asked questions
How do I find out what chord I am playing?
Tap the notes on the keyboard above. The finder looks for a root and chord type whose notes match exactly, and shows the best name first, with other possible readings below.
Why does it give more than one name?
The same notes can be named from different roots. C E G A is C6 (with C as home) or Am7 (with A as home). Setting the lowest note tells the finder which note is in the bass and narrows it down.
What is a slash chord?
A chord with a note other than the root in the bass, such as C/E (a C chord with E as the lowest note). It is written root, then a slash, then the bass note.
What does "no 5th" mean?
Seventh and ninth chords often leave out the perfect fifth because it adds little to the sound. If your notes match a chord except for its fifth, the finder tells you so.
How do I find the notes of a chord?
Switch to "Chord → notes", type the chord (for example Bbmaj7) and you get its notes spelled correctly, the formula, and the keys lit on the keyboard.
Can it identify a chord I play on guitar?
Work out the notes of each string first (or look them up) and tap them here. A guitar fretboard input is planned.