How does the ii–V–I progression lead back to the tonic in jazz?

In jazz, the ii–V–I progression is a fundamental sequence valued for its smooth, logical movement back to the tonic (I) chord, providing a clear sense of resolution.1

This progression functions by utilizing the inherent tension and pull of the dominant (V) chord toward the tonic. The dominant chord contains the "leading note"—the seventh note of the scale—which sits only a half step away from the tonic and exerts a strong gravitational pull toward it.2

In jazz, this effect is often intensified by using a dominant seventh chord ($V_7$). This chord includes two specific notes that pull strongly toward the tonic:
* The leading note (the seventh of the scale), which resolves to the tonic.2
* The fourth note of the scale, which resolves to the third of the tonic chord.2

Furthermore, the $V_7$ chord contains a tritone interval between these two notes. This dissonance demands resolution, which is satisfied when the chord moves to the tonic, creating a highly effective and satisfying harmonic release.2