I–IV–V–I

{{short description|Chord progression}}

{{Image frame|content=

{

\new PianoStaff <<

\new Staff <<

\new Voice \relative c'' {

\stemUp \clef treble \key c \major \time 4/4

c2 b c1

}

\new Voice \relative c' {

\stemDown

f2 d e1

}

>>

\new Staff <<

\new Voice \relative c' {

\stemUp \clef bass \key c \major \time 4/4

a2 g g1

}

\new Voice \relative c {

\stemDown

f,2_\markup { \concat { \translate #'(-4 . 0) { "C: IV" \hspace #2.2 "V" \hspace #5.3 "I" } } }

g c1 \bar "||"

}

>>

>> }

|width=300|caption=A perfect authentic cadence in four-part harmony}}

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."Jonas, Oswald (1982). Introduction to the Theory of Heinrich Schenker (1934: Das Wesen des musikalischen Kunstwerks: Eine Einführung in Die Lehre Heinrich Schenkers), p. 23. Trans. John Rothgeb. {{ISBN|0-582-28227-6}}. 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{{music|natural}} and eliminates the possibility of G major, which requires F{{music|#}}. 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 {{nihongo|"Komuro progression"|小室進行|komuro shinkō}}, namesake of Tetsuya Komuro who popularised the progression.{{cite journal|author=高増 明|date=October 31, 2015|title=日本のポピュラー音楽の機器と経済停滞|journal=関西大学社会学部紀要|publisher=関西大学社会学部|volume=47|issue=1|pages=1–20|hdl=10112/9455 |url=http://hdl.handle.net/10112/9455|issn=0287-6817|quote=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|trans-quote=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}}

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File:Bach - WTC II, Prelude in C Major.png's The Well-Tempered Clavier Book II, Prelude in C major.File:Bach - WTC II, Prelude in C Major IV-V-I.mid]]

File:Scarlatti - Sonata in D Minor, K. 517 IV-V-I.png's Sonata in D minor, K. 517.File:Scarlatti - Sonata in D Minor, K. 517 IV-V-I.mid]]