Diatonic 7th Chords: The Seventh-Chord Family of Every Key

The short answer: harmonize a major scale in three-note stacks and you get the key's basic chords; stack one more 3rd on each and you get its seventh chords — and the qualities always land in the same order: Imaj7, ii m7, iii m7, IVmaj7, V7, vi m7, vii m7♭5. Gitori's Diatonic 7th Chords course teaches you to derive that family from any key.

One pattern, twelve keys

The magic word is always. In C: Cmaj7, Dm7, Em7, Fmaj7, G7, Am7, Bm7♭5. In E♭: E♭maj7, Fm7, Gm7, A♭maj7, B♭7, Cm7, Dm7♭5. Different notes, identical quality sequence — because the pattern comes from the scale's structure, not the key (how harmonization works). Learn the sequence once and you know all 84 diatonic seventh chords in existence.

Two entries deserve special attention:

• V7 is the only dominant chord in the key. Hear a Dom7 and you've very likely located the V — a huge clue when finding a song's key.
• vii m7♭5 (half-diminished) is the odd one out — rare in pop, essential in jazz minor-key ii–V–i's.

What the course covers

The stacking process itself, why each degree produces the quality it does, and then drills: random key, random degree, name the seventh chord — until "the ii of A♭?" produces "B♭m7" without a pause. Reading a jazz lead sheet stops being decoding and starts being recognition.

Before you start

7th Chords (you need the four qualities cold) and Basic Chords before that. The Key Notes course helps, since harmonizing a key starts from knowing its notes.