In jazz and jazz harmony, "rhythm changes" refers to the chord progression occurring in George Gershwin's song "I Got Rhythm". This pattern, "one of the most common vehicles for improvisation," forms the basis of countless (usually uptempo) jazz compositions, was popular with swing-era musicians: It is found in "Shoeshine Boy" (Lester Young's 1936 breakout recording with Count Basie) and "Cotton Tail" written by Duke Ellington in 1940, as well as Charlie Christian's "Seven Come Eleven", Dizzy Gillespie's "Salt Peanuts", and Thelonious Monk's "Rhythm-a-Ning", for instance. 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 extremely 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 his estate.
| I vi | ii V | I vi | ii V |
| I I7 | IV iv | I V | I |
| Bbmaj7 G7 | Cm7 F7 | Bbmaj7 G7 | Cm7 F7 | | Fm7 Bb7 | Ebmaj7 Ab7 | Dm7 G7 | Cm7 F7 | | Bbmaj7 G7 | Cm7 F7 | Bbmaj7 G7 | Cm7 F7 | | Fm7 Bb7 | Ebmaj7 Ab7 | Cm7 F7 | Bbmaj7 |
| III7 | + | VI7 | + | | II7 | + | V7 | + | | D7 | + | G7 | + | | C7 | + | F7 | + |
This is known as the Sears Roebuck bridge, named after Sears, Roebuck and Co.
The B section is then followed by the second 8 bars of A section
Variant versions of changes are legion due to substitutions: bebop players, for instance, would often superimpose series of "two-fives" (passing sequences of minor-7th and dominant-7th chords) or other substitutions for interest or in order to discourage lesser musicians from sitting in on the bandstand. The B section may appear as follows:
or it may be lifted out of this progression and used in the middle of another piece as follows:
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 B section. "Scrapple from the Apple" uses the chord changes of "Honeysuckle Rose" for the A section, but replaces the B section with "Rhythm"'s III7-VI7-II7-V7 bridge. Other tunes, such as Sonny Stitt's "The Eternal Triangle" and the theme from "The Muppet Show", use the A section of "Rhythm" but have a different bridge. Tadd Dameron's "Good Bait" uses the A section of the Rhythm changes but a different progression for the bridge. Sometimes in rhythm changes tunes, the B section is left free for improvisation even during the head (e.g. in Sonny Rollins' "Oleo").
The following is a partial list of songs based on the rhythm changes:
- "Anthropology" (Charlie Parker/Dizzy Gillespie)
- "Cotton Tail" (Duke Ellington)
- "Dexterity" (Charlie Parker)
- "Fingers" (Thad Jones)
- "Five Guys Named Moe" (Louis Jordan and His Tympany Five)
- "Lester Leaps In" (Lester Young)
- "Little Pixie II" (Thad Jones)
- "Meet the Flintstones" (Hoyt Curtin)
- "Moose the Mooche" (Charlie Parker)
- "Oleo" (Sonny Rollins)
- "Rhythm-A-Ning" (Thelonious Monk)
- "Steeplechase" (Charlie Parker)
- "Straighten Up and Fly Right" (Nat King Cole)
- "Tip Toe" (Thad Jones)
- "You, Me, and the Bottle Makes Three Tonight (Baby)" (Big Bad Voodoo Daddy)
- "Race To The Bridge" (Gordon Goodwin)
- R., Ken (2012). DOG EAR Tritone Substitution for Jazz Guitar, Amazon Digital Services, Inc., ASIN: B008FRWNIW
- 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). Fascinating Rhythm: Reading Jazz in American Writing, p.17. ISBN 0-691-12357-8.
- Rust, Brian, Jazz and Ragtime Records, 1897-1942, 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.68.
- Ellis, Herb and Holmes, Terry (1996). The Herb Ellis Jazz Guitar Method: Rhythm Shapes, p.4-5. ISBN 9781576233412.
- Spitzer (2001), p.81.
- Rawlins, Robert and Bahha, Nor Eddine (2005). Jazzology: The Encyclopedia of Jazz Theory for All Musicians, p.128. ISBN 9780634086786.
- Holbrook, Morris B. (2008). Playing the Changes on the Jazz Metaphor, p.104. ISBN 9781601981721.
- Spitzer (2001), p.71.
- Spitzer (2001), p.72.