Chord progression

In a <a href="/facts/Musical_composition/EUR2qaQw">musical composition</a>, a chord progression or harmonic progression (informally chord changes, used as a <a href="/facts/Plural/3VjXP7VF">plural</a>) is a succession of <a href="/facts/Chord_(music)/hJBCHCSB">chords</a>. Chord progressions are the foundation of <a href="/facts/Harmony/Uwagvon2">harmony</a> in Western musical tradition from the <a href="/facts/Common_practice_period/nJ8HnoB2">common practice era</a> of <a href="/facts/Classical_music/oglVXmSb">Classical music</a> to the 21st century. Chord progressions are the foundation of <a href="/facts/Popular_music/Q5yhxIwY">popular music</a> styles (e.g., <a href="/facts/Pop_music/kgshFE5B">pop music</a>, <a href="/facts/Rock_music/zBM2guyQ">rock music</a>), <a href="/facts/Traditional_music/yFHpeE7k">traditional music</a>, as well as genres such as <a href="/facts/Blues/f2WSr9QQ">blues</a> and <a href="/facts/Jazz/lmUzXGq8">jazz</a>. In these genres, chord progressions are the defining feature on which <a href="/facts/Melody/5TR3IE3Y">melody</a> and <a href="/facts/Rhythm/aHAByx9M">rhythm</a> are built.
In tonal music, chord progressions have the function of either establishing or otherwise contradicting a <a href="/facts/Tonality/vBJp7QcT">tonality</a>, the technical name for what is commonly understood as the "<a href="/facts/Key_(music)/jo4UMbHp">key</a>" of a song or piece. Chord progressions, such as the extremely common chord progression I-V-vi-IV, are usually expressed by <a href="/facts/Roman_numeral_analysis/rwtlhyNE">Roman numerals</a> in Classical music theory. In many styles of popular and traditional music, chord progressions are expressed using the name and "<a href="/facts/Chord_quality/lv9LbnVT">quality</a>" of the chords. For example, the previously mentioned chord progression, in the key of E♭ major, would be written as E♭ major–B♭ major–C minor–A♭ major in a fake book or <a href="/facts/Lead_sheet/790UPN2U">lead sheet</a>. In the first chord, E♭ major, the "E♭" indicates that the chord is built on the <a href="/facts/Root_(chord)/BzI7uzCG">root note</a> "E♭" and the word "major" indicates that a <a href="/facts/Major_chord/RwuuqKYS">major chord</a> is built on this "E♭" note.
In rock and blues, musicians also often refer to chord progressions using <a href="/facts/Roman_numerals/7BA8nn78">Roman numerals</a>, as this facilitates transposing a song to a new key. For example, rock and blues musicians often think of the <a href="/facts/Twelve-bar_blues/NPuEjsWL">12-bar blues</a> as consisting of I, IV, and V chords. Thus, a simple version of the 12-bar blues might be expressed as I–I–I–I, IV–IV–I–I, V–IV–I–I. By thinking of this blues progression in Roman numerals, a <a href="/facts/Backup_band/BDNGTNNm">backup band</a> or <a href="/facts/Rhythm_section/tXJI24kX">rhythm section</a> could be instructed by a <a href="/facts/Bandleader/82qga80G">bandleader</a> to play the chord progression in any key. For example, if the bandleader asked the band to play this chord progression in the key of B♭ major, the chords would be B♭-B♭-B♭-B♭, E♭-E♭-B♭-B♭, F-E♭-B♭-B♭.
The complexity of a chord progression varies from genre to genre and over different historical periods. Some pop and rock songs from the 1980s to the 2010s have fairly simple chord progressions. <a href="/facts/Funk/NVuzVek1">Funk</a> emphasizes the <a href="/facts/Groove_(music)/Arh0e7WE">groove</a> and rhythm as the key element, so entire funk songs may be based on one chord. Some <a href="/facts/Jazz-funk/FV6UKkQV">jazz-funk</a> songs are based on a two-, three-, or four-chord <a href="/facts/Vamp_(music)/NEw7V2JM">vamp</a>. Some <a href="/facts/Punk_rock/voBjpcpS">punk</a> and <a href="/facts/Hardcore_punk/eonxzUyP">hardcore punk</a> songs use only a few chords. On the other hand, <a href="/facts/Bebop/Q6suehVl">bebop</a> jazz songs may have <a href="/facts/32_bar_song_form/sqmXfyzu">32-bar song forms</a> with one or two chord changes every bar.

Chord progression open-in-new

Chord progression