Rhythm changes are a common 32-bar chord progression in jazz, originating as the chord progression for George Gershwin's "I Got Rhythm". The progression is in AABA form, with each A section based on repetitions of the ubiquitous I–vi–ii–V sequence (or variants such as iii–vi–ii–V), and the B section using a circle of fifths sequence based on III7–VI7–II7–V7, a progression which is sometimes given passing chords.
This pattern, "one of the most common vehicles for improvisation," forms the basis of countless (usually uptempo) jazz compositions and was popular with swing-era and bebop musicians. For example, it is the basis of "Shoeshine Boy" (Lester Young's 1936 breakout recording with Count Basie) and Duke Ellington's "Cotton Tail" as well as Charlie Christian's "Seven Come Eleven," Dizzy Gillespie's "Salt Peanuts," and Thelonious Monk's "Rhythm-a-Ning". The earliest known use of rhythm changes was by Sidney Bechet in his September 15, 1932 recording of "Shag" with his "New Orleans Feetwarmers" group.
This progression's endurance in popularity is largely due to its extensive use by early bebop musicians. The chord changes began to be used in the 1930s, became common in the '40s and '50s, and are now ubiquitous. First, "I Got Rhythm" was by then already a popular jazz standard. Second, by listening to the song and writing a new melody over its chord changes, thereby creating a composition of a type known as a contrafact, a jazz musician could claim copyright to the new melody rather than acknowledge Gershwin's inspiration and pay royalties to Gershwin's estate. Third, using a stock, well-known progression for new melodies made it easier to perform a song at jam sessions, shows, and recordings because the bandleader could tell new musicians that the song uses rhythm changes and note any modifications and chord substitutions.
I vi ii V I vi ii V I I7 IV iv I V I
In a jazz band, these chord changes are usually played in the key of B♭ with various chord substitutions. Here is a typical form for the A section with various common substitutions, including VII7 in place of the minor vi chord; the addition of a ii–V progression (Fm7–B♭7) that briefly tonicizes the IV chord, E♭; and using iii in place of I for the final four bars of the A section:
The "bridge" consists of a series of dominant seventh chords (III7–VI7–II7–V7) that follow the circle of fourths (ragtime progression), sustained for two bars each, greatly slowing the harmonic rhythm as a contrast with the A sections. This is known as the Sears Roebuck bridge, named after Sears, Roebuck and Co.
The B section is followed by a final A section
Variant versions of changes are common due to the popularity of adding interest with chord substitutions, passing chords and changes of chord quality. Bebop players, for instance, would often superimpose series of ii–V (passing sequences of minor seventh and dominant seventh chords) or other substitutions for interest or in order to discourage less experienced musicians from "sitting in" on the bandstand. The opening I chord was often B♭6 in Gershwin's original, but beboppers changed it to B♭M7 or B♭7. For instance, the B section may appear as follows:
An even more adventurous bebop-style substitution is to convert C7 | C7 | F7 | F7 to Gm7 | C7 | Cm7 | F7, and then to further develop this substitution by changing this to Am7 D7 | Gm7 C7 | Dm7 G7 | Cm7 F7.
The following is a partial list of songs based on the rhythm changes:
- "Anthropology" (Charlie Parker/Dizzy Gillespie)
- "Cotton Tail" (Duke Ellington)
- "Crazeology" (Benny Harris)
- "Dexterity" (Charlie Parker)
- "The Eternal Triangle" (Sonny Stitt)
- "Lester Leaps In" (Lester Young)
- "Moose the Mooche" (Charlie Parker)
- "Oleo" (Sonny Rollins)
- ”Passport” (Charlie Parker)
- ”O Latido do cachorro” (David Feldman (musician))
- "Rhythm-A-Ning" (Thelonious Monk)
- "The Serpent's Tooth" (Miles Davis)
- "Steeplechase" (Charlie Parker)
- "Straighten Up and Fly Right" (Nat King Cole)
- "The Theme" (Miles Davis)
- "Tiptoe" (Thad Jones)
The component A and B sections of rhythm changes were also sometimes used for other tunes. For instance, Charlie Parker's "Scrapple from the Apple" and Juan Tizol's "Perdido" both use a different progression for the A section while using the rhythm changes bridge. "Scrapple from the Apple" uses the chord changes of "Honeysuckle Rose" for the A section but replaces the B section with III7–VI7–II7–V7.
- Spitzer (2001), p. 68.
- Dziuba, Mark (2003). The Big Book of Jazz Guitar Improvisation, p. 140. ISBN 9780739031728.
- "Duke Ellington the Man and His Music", p.20. Luvenia A. George. Music Educators Journal, Vol. 85, No. 6 (May, 1999), pp. 15–21. Published by: MENC: The National Association for Music Education.
- Yaffe, David (2005). As well found in Olav Jullums composition "bedroom leavs". Fascinating Rhythm: Reading Jazz in American Writing, p. 17. ISBN 0-691-12357-8.
- Rust, Brian, Jazz and Ragtime Records, 1897–1942 Archived 2009-02-09 at the Wayback Machine, Mainspring Press, 2008.
- "Rhythm Changes," MoneyChords (angelfire.com). Includes an extensive listing of tunes utilizing these chord changes.
- Spitzer, Peter (2001). Jazz Theory Handbook. p. 67. ISBN 0-7866-5328-0.
- Thomas, John (2002). Voice Leading for Guitar: Moving Through the Changes, p. 85. ISBN 0-634-01655-5.
- Spitzer (2001), p. 81.
- Ellis, Herb and Holmes, Terry (1996). The Herb Ellis Jazz Guitar Method: Rhythm Shapes, pp. 4–5. ISBN 9781576233412.
- Holbrook, Morris B. (2008). Playing the Changes on the Jazz Metaphor, p. 104. ISBN 9781601981721.
- Rawlins, Robert and Bahha, Nor Eddine (2005). Jazzology: The Encyclopedia of Jazz Theory for All Musicians, p. 128. ISBN 9780634086786.
- Levine, Mark (1995). The Jazz Theory Book. Petaluma, California: Sher Music Co. p. 237. ISBN 1883217040. OCLC 34280067.
- Spitzer (2001), p. 71.
- Spitzer (2001), p. 72.
- R., Ken (2012). DOG EAR Tritone Substitution for Jazz Guitar, Amazon Digital Services, ASIN: B008FRWNIW