I–IV–V–I explained

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:

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]." In the key of C, IV provides the note F and eliminates the possibility of G major, which requires F. The progression is also often used at the end of works and sections.

A popular variant is vi–IV–V–I, commonly known as the, namesake of Tetsuya Komuro who popularised the progression.^[2]

See also

• Predominant chord
• Three-chord song
• V–IV–I turnaround
• ii–V–I progression
• Ragtime progression

Notes and References

1. [Oswald Jonas|Jonas, Oswald]
2. 高増 明. October 31, 2015. 日本のポピュラー音楽の機器と経済停滞. 関西大学社会学部紀要. 関西大学社会学部. 47. 1. 1–20. 10112/9455 . 0287-6817. 他にも… 小室進行（小室哲哉は、1990年代に多くのヒット曲を生み出したアーティスト・作曲家・プロデューサーで、小室が好んで使用したコード進行のパターン）といった定型化されたコードパターンが使われることが多い… 小室進行：Am → Dm（F）→ G → C. There are other standardised chord progressions, such as... the Komuro progression (a chord progression favoured by Tetsuya Komuro, an artist, composer and producer who created many hit songs in the 1990s)... Komuro progression: Am → Dm(F)→ G → C.