Colin Sapp
This page illustrates the “genetic” connection between various chord types. I’ve used the key of C as the reference point in all of these examples to keep the information relatively concise. Memorize these equivalencies so the chords become interchangeable in your mind. Also, mentally categorize their sound so you can determine how to utilize them. Then transpose them to all keys and practice incorporating them into your compositions and improvisation.
Basic Chord Equivalencies
These are chords that share the exact same pitches, but when a different degree is designated as the root, the name of the chord changes.
E+ = G#+ = C+
D#dim7 = F#dim7 = Adim7 = Cdim7
Am7 = C6
Am7b5 = Cm6
Gsus4 = Csus2
Fsus2 = Csus4
Eb6sus4 = Cm7#5
Rootless Equivalencies
These are common chords that exist within other chord types.
Triads
Eb is a rootless Cm7
Em is a rootless Cmaj7
Edim is a rootless C7
D#dim is a rootless Cdim7
E is a rootless Cmaj7#5
Eb+ is a rootless Cm(maj7)
B is a rootless Cdim(maj7)
Seventh Chords
Ebmaj7 is a rootless Cm9
Ebmaj7b5 is a rootless Cm6/9
Ebmaj7#5 is a rootless Cm9(maj7)
Eb7 is a rootless C7b9/#9
Eb7sus4 is a rootless C7#5 b9#9
Ebm(maj7) is a rootless Cm7b5(9)
Em7 is a rootless Cmaj9
Em7b5 is a rootless C9
Emaj7b5 is a rootless C7#5#9
E7 is a rootless Cmaj9#5
E7b5 is a rootless C9#5
Edim7 (Gdim7, A#dim7, C#dim7) is a rootless C7b9
Edim(maj7) is a rootless C7#9
F#m7 is a rootless C7b5/b9/13
Gb7 is a rootless C7b5b9
Gb7#5 is a rootless C9b5
Gmaj7 is a rootless Cmaj9#11
Gm7 is a rootless C9sus4
Gm7b5 is a rootless C7b9sus4
A7 is a rootless C7b9/13
A7sus4 is a rootless C6/9
Bb7b5 is a rootless C9#5
Bbm7b5 is a rootless C7#5b9
Bbdim(maj7) is a rootless C7b9/13
Bbmaj7b5 is a rootless C9/13
Slash Chords
Chords can also be expressed as triads and seventh chords over different bass notes. These yield chord equivalencies as well when allowing for enharmonic re-spelling.
Db/C = Dbmaj7
Db+/C = Dbmaj7#5
Dbdim/C = Dbdim(maj7)
Dbmaj7/C = Dbmaj7
D/C = D7
D7/C = D7
Dm/C = Dm7
Dm7/C = Dm7
Ddim/C = Dm7b5
D+/C = D7#5
Dsus2/C = C6/9
Eb/C = Cm7
Ebmaj7/C = Cm9
Ebm/C = Cm7b5
Ebm7/C = Cm9b5
Eb+/C = Cm(maj7)
Ebdim/C = Cdim7
Ebsus2/C = Cm11
E/C = Cmaj7#5
E7/C = Cmaj9#5
Em/C = Cmaj7
Em7/C = Cmaj9
Edim/C = C7
E+/C = C+
Esus2/C = Cmaj7#11
F/C = F
Fm/C = Fm
F+/C = Dbmaj7#5
Fmaj7/C = Fmaj7
Fm7/C = Fm7
F7/C = F7
Fsus2/C = Fsus2
Gb/C = C7b5b9
Gb+/C = D7#5
F#m/C = C13b5b9
F#m7/C = C13b5b9
Gb7/C = C7b5b9
F#dim/C = F#dim
Gbsus2/C = C7b5#5b9
G/C = Cmaj9
Gmaj7/C = Cmaj9#11
Gm/C = Cm9 or C9
Gm7/C = C9sus4
Gdim/C = C7b9
G+/C = Cm(maj7)
Gsus2/C = C6/9
Ab/C = Ab
Abmaj7/C = Ab
G#m/C = Cm(maj7)#5
Ab7/C = Ab7
G#+/C = C+
Absus2/C = Cm7#5
A/C = C13b9
Amaj7/C = C7#5/b9/13
A7/C = C13b9
Am/C = Am
Am7/C = Am7
A+/C = Dbmaj7#5
Adim/C = Adim
Asus2/C = Cmaj7(13)
Bb/C = C9sus4
Bbmaj7/C = C7sus4/9/13
Bb7/C = C9sus4b13
Bbm/C = C7b9sus4
Bbm7/C = C7sus4 b9b13
Bb+/C = D7#5
Bbsus2/C = C7sus4
A#dim/C = C7b9
B/C = Cdim(maj7)
Bm/C = D13
Bm7/C = D13
B7/C = Cdim(maj7)13
B+/C = Cm(maj7)
Dbm/C = Dbm(maj7)
Dbsus2/C = C7#5/b9/#9
Tension Substitutions
When tensions are substituted for chord tones, the result sometimes yields common chord types. Many of them have already been included in categories above, but here are examples that have not been mentioned.
F#m7b5 (11 for 3) = Cmaj7b5
F#m7b5 (9 for 1 and 11 for 3) = Cmaj7#5
Gm7 (11 for 5) = C7sus4
Advanced Chord Equivalencies
These are common chord types that can function as chords in other keys when allowing for incomplete chord spellings.
Ab7 = C7#5#9
Ab7#5 = C7b5#5
Dm7#5 = C9sus4
D7sus4 = C6/9