Chord family · 6 shapes
Extended and altered chords
An extension adds a note beyond the seventh, while an alteration changes a chord tone. Cm9 extends Cm7 with D; Dm7b5 alters Dm7 by lowering A to Ab. Both names describe specific notes rather than a playing style.
The half-diminished chord has the formula 1, flat 3, flat 5 and flat 7. In Dm7b5 those notes are D, F, Ab and C. It is the ii chord of a minor-key ii–V–i such as Dm7b5, G7 and Cm.
half-diminished
5 shapes · 4 with their own pageminor ninth
1 shapes · 1 with their own pageHow to use extended and altered chords in a song
Compare Dm7 with Dm7b5 by listening for the fifth. A becomes Ab. The diagrams may use different string sets, so a one-note harmonic change does not always mean moving just one finger.
Cm9 contains C, Eb, G, Bb and D. The diagram here puts Eb on the D string at fret 1, preserving the minor third while a small barre at fret 3 covers the upper strings. Check that Eb rings before strumming.
Dim7 is a separate four-note chord with formula 1, flat 3, flat 5 and double-flat 7. Its note set repeats under a three-semitone transposition. A three-note dim triad does not have that symmetry.
The charts below focus on m7b5 and m9. Major ninths and thirteenths are further extensions, but their diagrams are not included here. Start with the minor ii–V–i and learn each chord on a comfortable string set.
If you only try two of the shapes on this page, try F#m7b5: both can be reached from shapes you already know, so the change stays playable at speed. Listen to the chord that follows it in the loop — the resolution is the point of the chord, not the chord itself.
How to practise extended and altered chords
- Compare Dm7 with Dm7b5, picking the A then Ab separately. Use the diagrams to choose the grips.
- Loop Dm7b5, G7 and Cm slowly, one chord per bar. Listen to the dominant G7 resolving into Cm.
- Compare Cm7 with Cm9. The added D is the ninth; keep Eb audible so the chord retains its minor colour.
Extended and altered chords in real songs
The half-diminished chord is the standard two chord of a minor key, so it appears in every jazz standard charted here. Five examples:
- Autumn Leaves: Am7b5 is the first chord of the tune and the one every guitarist learns the shape from
- Blue Bossa: Em7b5 leads into A7, the ii–V of the whole piece
- My Funny Valentine: uses Dm7b5 and Cm9 in the same phrase, the half-diminished and the minor ninth side by side
- Black Orpheus: Dm7b5 and Cm9 carry the opening bars of the bossa nova
- Fly Me to the Moon: Bm7b5 to E7 to Am is the minor ii–V–i in its textbook form
Printable family chart
Extended and altered chords with their own pages
These are the ones that turn up often enough in songs to deserve a full page — fingerings in every position, real progressions, and the songs that use them.