How to use the chord identifier from notes
- Type the notes of the chord, separated by spaces or commas: C, F#, Bb, Eb4. Octave numbers are ignored and repeats do not matter.
- Leave The first note is the lowest note ticked to name inversions and slash chords from the bass, or untick it to list names by how common the chord shape is.
- Choose whether to show notes in your spelling, with sharps or with flats.
- Read the best name and the table of every other name that fits the same notes.
Formula
Reduce each note to a pitch class from 0 (C) to 11 (B)
For each note taken as the root, list the semitone distances above it
Match that set to a chord shape, such as major (0, 4, 7) or minor seventh (0, 3, 7, 10)
If the bass is not the root, write the name as a slash chord: root name / bass
The library has 26 shapes: major, minor, diminished, augmented, suspended, power chords, sixths, sevenths, added-note chords and a few ninths. A chord matches only when its notes are exactly the notes you gave.
Inversions and shared notes
E G C with E in the bass is a C major chord in first inversion, so the name is C/E and the bass is the major third. The notes C E G B give Cmaj7, and Bb D F Ab give Bb7 (A#7 if you choose sharps).
The four notes A C E G fit two names at once. With A in the bass the best name is Am7 and the other is C6/A. If C is in the bass, the best name becomes C6 and the other Am7/C. The notes alone cannot decide; the key and the music around the chord do.
Why one chord can have several names
A chord is a set of notes, and many sets can be read from more than one root. A minor seventh chord built on A has the same notes as a major sixth chord built on C, and a diminished seventh chord can be read from any of its four notes. The page shows every matching reading and puts the one that has the bass note as its root first. For choosing between them, the surrounding chords and the key matter more than the note set.
To move chords to another key, use the chord transposer. To see chord progressions in a key, the chord progression generator helps, and the musical scale generator lists the notes of each scale.
What it can and cannot name
Chords with omitted or altered notes, such as a ninth chord with no fifth, or stacked extensions beyond the library, may not match any name. In that case the page says so and lists the notes. Remove a passing note or add the missing third or fifth to find a nearby name. The page reads written note names only. It does not listen to audio.
Assumptions and limits
- Notes are read as written pitch classes. C# and Db are the same note, and octaves do not matter.
- The first note you type is taken as the bass when the box is ticked. Spacing and voicing are not analyzed.
- A name is shown only when the notes match a shape in the library exactly, with no missing or extra notes.
- Double sharps and flats are accepted and shown in your spelling only when it matches a note you typed.
Frequently asked questions
What is a slash chord?
It is a chord with a bass note other than its root, written as chord name over bass, such as C/E. The bass is one of the chord notes in an inversion, or a different note added underneath.
Why does the same set of notes have two names?
Some sets can be built from more than one root. A minor seventh chord has the same notes as the major sixth chord a minor third above its root, so Am7 and C6 are the same four notes read two ways.
Can it name a chord from a guitar fingering?
Yes, if you type the note names of the strings you play. Enter each note once; repeated notes in different octaves are the same pitch class and do not change the result.
Why is there no name for my chord?
The chord may use notes in a combination outside the library, or leave out a note that defines the name. Try adding or removing one note to see which names are close.