Chord progression
ii–V–I chord progression
The backbone of jazz harmony: a minor seventh, a dominant seventh and home. Learn it in all twelve keys and you can read most standards.
ii7–V7–Imaj7 in all 12 keys
Every row is the same progression moved to another key. Tap a chord for its shapes, or play a row to hear it.
Why ii7–V7–Imaj7 works
Each root is a fifth below the one before, the strongest root movement in harmony. The ii chord prepares, the V7 chord creates tension with its tritone between the third and the seventh, and the Imaj7 releases it. Between ii and V only one note changes, and between V and I the two tense notes each move by a half step.
On piano, the classic voicing keeps the hands nearly still: the seventh of each chord falls by a half step to become the third of the next. Listen for that line in the playback; it is the sound of jazz voice leading.
How to practise it
Play two beats on ii, two on V and four on I. Go through the table one key at a time, and once you can, move down the circle of fifths so the I of one key becomes the ii of the next.
Use the metronome: start around 70–80 BPM with two or four beats per chord, and change chords exactly on the first beat. When the changes are clean, raise the tempo in small steps and try the same pattern in two or three other keys from the table.
Choosing a key
The numerals stay the same in every key, which is the point of learning ii7–V7–Imaj7 as a pattern rather than as a list of chords. Play it in C until it is comfortable, then pick a row from the table that suits your voice. Guitarists can use a capo to keep the easy open shapes while the music sounds higher.
Variations
In minor keys it becomes iiø7–V7–i. Add ninths or a flat nine on the V for more colour, or replace V7 with a dominant a tritone away (a tritone substitution) for a smooth chromatic bass.