---
title: The ii-V-I
category: Jazz Harmony
slug: ii-v-i
related: [seventh-chords, voice-leading, chord-scale-theory, tritone-substitution]
url: https://fourthshub.com/docs/ii-v-i
---

# The ii-V-I

The **ii-V-I** is the most fundamental chord progression in jazz and a cornerstone of Western tonal harmony. Understanding it is non-negotiable for any serious musician.

## The Progression

In the key of C major:

- **ii**: Dm7 (D-F-A-C)
- **V**: G7 (G-B-D-F)
- **I**: Cmaj7 (C-E-G-B)

This sequence works because of **functional harmony**: the ii chord (subdominant function) creates moderate tension, the V chord (dominant function) creates maximum tension via its tritone (B-F), and the I chord (tonic function) resolves that tension.

## Why It Works

The tritone between the 3rd (B) and 7th (F) of G7 resolves by contrary half-step motion: B moves up to C (the root of Cmaj7) and F moves down to E (the 3rd of Cmaj7). This voice-leading resolution is the engine that drives tonal music.

The ii chord prepares the V by establishing the key center and creating a stepwise bass line: D -> G -> C (descending by 5th, the strongest root motion in music).

## Minor ii-V-i

In minor keys, the progression becomes:

- **ii**: Dm7b5 (half-diminished)
- **V**: G7(b9) or G7alt (often with altered tensions)
- **i**: Cm7 or CmMaj7

The half-diminished ii chord and altered dominant V chord create the darker sound appropriate for minor resolution.

## Variations

**Backdoor ii-V**: Uses bVII7 instead of V7 (e.g., Bb7 -> Cmaj7). A surprising, warm approach to tonic.

**Tritone sub ii-V**: Replaces V7 with bII7 (e.g., Db7 -> Cmaj7). Since Db7 shares the same tritone as G7, the resolution works with a chromatic bass line.

**Extended ii-V-I**: Adding the vi chord before ii creates a vi-ii-V-I turnaround (Am7-Dm7-G7-Cmaj7).

## In Practice

The ii-V-I appears constantly in jazz standards. "Autumn Leaves" is built almost entirely from ii-V-Is in two keys. Learning to recognize, hear, and play ii-V-I progressions in all 12 keys is one of the most important skills in jazz.

In fourths tuning, the same voicing shapes and fingerings work in every key — you learn one set of ii-V-I voice leadings and shift position for all 12 keys.