Music Sound

Rhythm section refers to the musicians whose primary jobs in a jazz or popular music band or ensemble is to establish the rhythm of a song or musical piece, often via repeated riffs or ostinati. "Rhythm Section" may also refer to the instruments in this group.

A non-musician might call the rhythm section 'background music'. However, their importance is much greater than that.

In theory (and sometimes in practice) any instrument or instruments can provide a steady rhythm (listen to Jimmy Giuffre's clarinet-valve trombone-guitar trio of the late 1950s for example), and "rhythm" instruments often take featured solos, especially in jazz.

However, certain instruments are generally part of a rhythm section: The drum set and bass guitar (or sometimes double bass) are usually the critical. Chordal instruments such as rhythm guitar, (sometimes Banjo), piano or other keyboard instruments,(such as the electric piano) and vibraphone are often used, as well as auxiliary percussion and/or other instruments. These other instruments are usually not prime contributors to the rhythm section.

In some relatively uncommon instances, the lower octaves of a piano, organ, or electronic keyboard may substitute for bass guitar or double bass. One of the best known examples of this was keyboardist Ray Manzarek of The Doors. In the absence of a bassist, a keyboardist can also use a keyboard bass, or bass pedals that can be played with the feet.

Some jazz bands use tuba or other low-pitched instruments in place of the more common double bass, either due to practical considerations (no bassist is available) or due to a preference for the alternative instrument. These substitute instruments sound different from a double bass or bass guitar, and can offer a unique quality. The tuba may be used as a means of evoking brass band sounds reminiscent of early jazz, such as New Orleans or Dixieland Swing.

Another suggested origin of the term is that it refers to the ubiquity in jazz of rhythm changes, the chord progression of George and Ira Gershwin's "I've Got Rhythm" (1930), the claim being that backing musicians were so frequently called upon to improvise against these chord changes that they were eventually referred to as a "rhythm section". (This information putatively from a Keyboard magazine article from the mid-nineties.)