Chord Identifier
Help identify the chord you are playing!
Most of the responses on here are trying to come up with the ‘correct’ answer to the question, which, as you can see, is very difficult to get musicians to agree on. I think a ‘useful’ answer is much easier to come up with. For me, the simplest and most helpful way to think of chords is by organizing them into 9 ‘types’: 4 triads and 5 7th chords. Here they are along with their chord tones as degrees of the major scale.
Triads
Major (1, 3, 5)
Minor (1, ♭3, 5)
Diminished (1, ♭3, ♭5)
Augmented (1, 3, ♯5)
An interesting way to think of 7th chords is by starting with a major 7th chord and lowering one note at a time. Try playing this and see how it sounds.
Major 7th (1, 3, 5, 7)
Dominant 7th (1, 3, 5, ♭7)
Minor 7th (1, ♭3, 5, ♭7)
Half diminished (1, ♭3, ♭5, ♭7)
Fully diminished (1, ♭3, ♭5, ♭♭7)
This list covers all the chords I ever use in performing and arranging. All of them except 2 (augmented and fully diminished) can be found in the diatonic scale. Chord extensions can always be added to change their flavor, but they don’t fundamentally change the function of the chord.
This thread has gotten too mathematical. If you want to consider every possible combination of notes it’s an extreme number. But I don’t think that’s useful. If we consider chord types on any root we can immediately divide by 12. If we consider extensions as variations of more basic types we can make finite and useful categories:
Major: triad and major 7th:
C, CMaj7: C E G B
Dominant: triad and 7th:
C, C7: C E G Bb
A triad can only be considered dominant by context.
Minor: triad and 7th:
Cm, Cm7: C Eb G Bb
A minor triad can add a major 7th to form a mMaj7 chord. This is isn’t common.
CmMaj7: C Eb G B
Suspended: triad and 7th:
Csus, C7sus: C F G Bb
Suspended triads can occur in any context and the suspended 4th can resolve to become a major or minor triad. Suspended 7ths are often in a dominant context.
Diminished: triad and 7ths (2 types):
Cm7b5: C Eb Gb Bb
Cdim7: C Eb Gb Bbb(A)*
Diminished triads are rare. Diminished chords are usually 7ths and have two types that can occur in different contexts. Half diminished or m7b5 usually precedes a dominant but can substitute for dominant in a major key. Fully diminished chords almost always act as a substitute dominant. This chord has a diminished 7th interval from the root, built on C this is Bbb, it’s enharmonic to A, which is the key or fret that would be played on piano or guitar.
Augmented: triad and 7ths (2 types)
Caug: C E G#
CMaj7#5: C E G# B
C7#5: C E G# Bb
Augmented major 7th chords aren’t common. Augmented dominant chords are occasionally used.
Now we can categorize some common variations:
A 6th can be added to a major or minor triad:
C6: C E G A
Cm6: C Eb G A
A 2nd can be used instead of a 4th in a suspended chord, sometimes both:
Csus2: C D G
Extensions are 9th, 11th, and 13th:
CMaj9: C E G B D
Cm9: C Eb G Bb D
C9sus(C11): C F G Bb D
The suspended 4th is the same note as the 11th so this chord can be written both ways.
Cm11: C Eb G Bb D F
The 11th forms an awkward dissonance with the major 3rd. The 3rd is usually omitted from a dominant 11th. The 11th is almost never added to a major 7th chord but it can be raised.
CMaj7#11: C E G B D F#
The 13th is almost always part of a dominant chord. It can be optionally added to a major 7th chord but isn’t usually specified in a chart. Minor 13th chords are considered awkward sounding and rarely used.
C13: C E G Bb D A
C13sus: C F G Bb D A
The 11th (F) is dissonant and almost always omitted unless the chord is suspended.
A 9th can be added to a triad without including the 7th:
Cadd9: C E G D
Cmadd9: C Eb G D
Altered dominants may have any combination of raised or lowered extensions, 5ths can be altered and an altered dominant can also be suspended. I won’t list all the possibilities. Here are some common examples:
C7b9: C E G Bb Db
C7b9sus: C F G Bb Db
C7#11: C E G Bb D F#
C7#9#5: C E G# Bb D#
Sometimes the abbreviation alt. is used. Performers are free to choose from the all the possible alterations: b5, #5, b9, #9, #11, b13
C7alt.: C E (Gb, G#) Bb (Db, D#) F# Ab
Chords don’t always have the root in the bass. If the note is part of the chord it’s called an inversion. This is shown with a slash: chord/bass note Examples:
C/E (1st inversion)
C/G (2nd inversion)
Sometimes the bass note isn’t in the chord. If the note is the 7th of the chord it’s still an inversion.
C/B = CMaj7 (3rd inversion)
C/Bb = C7 (3rd inversion)
Any other note will sound like the root and will form another chord. These slash chords are a just a simplified way of writing another chord.
C/A = Am7
Cm/Ab = AbMaj7
Major 7th and minor 7th chords are common so they’re rarely written this way.
C/F = FMaj7sus2 or FMaj9no3
C/D = D9sus or D11
CMaj7/D = D13sus
Cm/D = D7b9sus