I–IV–V–I

In music, I–IV–V–I or IV–V–I is a chord progression and cadence that, "unequivocally defines the point of origin and the total system, the key.

"[1] Composers often begin pieces with this progression as an exposition of the tonality:[1] According to theorist Oswald Jonas, "[a]long with motion toward the fifth (V), IV [the subdominant] appears as a corrective, depriving V (the dominant) of its independence and pointing it back in the direction of its origin [I].

"[1] In the key of C, IV provides the note F♮ and eliminates the possibility of G major, which requires F♯.

[1] The progression is also often used at the end of works and sections.

[2] This music theory article is a stub.

I–IV–V–I chord progression in J.S. Bach 's The Well-Tempered Clavier Book II, Prelude in C major. [ 1 ]
I–IV–V–I chord progression in Scarlatti 's Sonata in D minor, K. 517. [ 1 ]