A rhythm section is a group of musicians within a music ensemble or band that provides the underlying rhythm, harmony and pulse of the accompaniment, providing a rhythmic and harmonic reference and "beat" for the rest of the band. The rhythm section is often contrasted with the roles of other musicians in the band, such as the lead guitarist or lead vocals whose primary job is to carry the melody.
The core elements of the rhythm section are usually the drum kit and bass. The drums and bass provide the basic pulse and groove of a song. The section is augmented by other instruments such as keyboard instruments and guitars that are used to play the chord progression upon which the song is based. The bass instrument (either double bass, or electric bass guitar, or another low-register instrument such as the synth bass, depending on the group and its style of music) plays the low-pitched bassline. The bassline is a musical part that supports the chord progression, typically by playing a musically interesting bassline that outlines the important notes of the harmony, often by emphasizing the root, fifth, and third of each chord.
The term is common in modern small musical ensembles, such as bands that play jazz,Randel, Don Michael (1999). "Rhythm section" in The Harvard Concise Dictionary of Music and Musicians; p. 560. country, blues, and rock. Orchestras that play popular music, film soundtracks (often called a "pops orchestra"), or musical theatre orchestras may also feature a rhythm section (at a minimum drum kit and electric bass/amplified double bass, but possibly including keyboards and guitar) that performs with the larger ensemble. The rhythm section provides a rock or pop feel and sounds that would be difficult to recreate with orchestral instruments.
Instruments
A typical rhythm section comprises one or more guitars (either electric guitars, in rock music bands; acoustic guitars, in country music, folk music and blues or both electric and acoustic in some bands); and/or a keyboard instrument (piano, electric piano, Hammond organ, synthesizer, etc.) a double bass, an acoustic bass guitar, or an electric bass guitar (depending on the style of music), and drums (usually acoustic, but in some post-1980s styles, the drums may be electronic drums).
In some styles of music, there may be additional percussionists playing instruments such as the djembe or shakers. Some styles of music often have two electric guitarists, such as rock genres like heavy metal music and punk rock. Some styles of music use multiple keyboard instrument performers simultaneously (e.g., piano and Hammond organ or electric piano and synthesizer) for a fuller sound. A rhythm section could be as small as two or three instruments (e.g., a guitarist and a bassist or a power trio of bass, drums and guitar) or it may be a fairly large ensemble with several keyboardists, several guitarists, auxiliary string players (mandolin, ukulele, etc.), a drummer and percussionists.
The largest rhythm sections may be led by a bandleader or a conductor who indicates the tempo of each song, starts each song, leads slow-downs of the music at cadences (sections of songs where the music comes to rest on a chord), and indicates when to change soloists and how and when the song will end.
The instrumentalists used in a rhythm section vary according to the style of music and era. Modern pop, rock and jazz band rhythm sections typically consist of a drummer, a bass player, and one or more players of chordal instruments (e.g., a pianist, guitarist, etc.).Jazz Drum Lessons - Drumbook.org The term rhythm section may also refer to the instruments in this group (named collectively the "rhythm section instruments").
Klezmer bands rarely have percussion, but rely heavily on a bass instrument, often brass, and a piano or accordion. Traditional dance music bands from Central and Eastern Europe often build their rhythm section around a double bass and viola - the musician designated with the German term "Bratscher".
In music industry parlance, the amplifiers and some of the instruments are nicknamed the "backline." Backline instruments are commonly provided for bands at music festivals and other concerts where several bands will play during an event. By providing these backline instruments, the changeover process is quickened when new bands take the stage. The backline typically consists of large and heavy items that are hard to transport; this may include large bass amplifiers and guitar amplifiers and their speaker cabinets, a drum kit (with or without cymbals and a snare drum, which drummers often provide themselves), a Hammond organ, stage piano, and a keyboard amplifier.
Notwithstanding being provided amplifiers, an instrumentalist almost always needs to bring their own instrument (i.e. a guitar or bass). A venue often informs musicians about which instruments are supplied as the backline for a given performance, and in many cases, the contract signed by the band and the venue/promoter contains an explicit list of the backline gear that will be on stage, even specifying brand names and model numbers.
Roles
In modern rock music, a rhythm guitarist specializes in rhythmic and chordal playing (as opposed to the melodic guitar solos and lead melody lines played by the lead guitar), often repeating quaver (eighth-note), half note or whole note chords. In the louder genres, such as hard rock, heavy metal, and punk rock, rhythm guitarists often play power chords with distortion. Rhythm guitarists often strum open chords in pop, rock, country, and folk music and play barre chords in many pop and rock styles.
Although rhythm sections spend much of the time providing accompaniment (backing parts) for songs, in some cases they provide other musical roles. In some songs or styles of music, instruments from the rhythm section may play soloistic roles on occasion (e.g., improvised guitar solos or solo breaks) or play a melodic role (e.g., a rhythm guitarist may play a lyrical countermelody behind a singer or a melodic intro line before the lead vocalist starts to sing). Since rhythm sections generally provide the background music for lead instruments and solo singers, rhythm sections are typically not as prominent as a singer or soloist. However, since rhythm sections provide the underpinning for a good performance by the lead instruments and vocalists, good rhythm sections are valued in the music industry. Some of the most accomplished rhythm sections have become famous, such as The Band, the E Street Band and Sly Dunbar and Robbie Shakespeare (the latter in reggae). In some popular bands, all of the band members, including rhythm section members, have become famous as individuals (e.g., the rhythm section members of The Beatles, The Rolling Stones, The Who, etc.).
In almost all genres of popular music and traditional music that use rhythm sections, ranging from rock to country to jazz, the rhythm section members are expected to be able to improvise (make up) their parts or prepare their own parts for a given song by listening to the CD at home. Once the bassist and chord-playing instruments are provided with the chord progression on a lead sheet (in which chords are typically named using the root note of the chord and its quality; e.g., C Major, d minor, G7, etc.), they are expected to be able to improvise or prepare a bass line and chord voicings, respectively, that suit the style of the song.
In each style of music, there are different musical approaches and styles that rhythm section members are expected to use. For example, in a country music song the guitarist will be expected to be able to perform a chord progression using an intricate fingerpicking style; in a heavy metal song, the guitarist will be expected to play power chords and complex, precise rhythmic patterns; in a jazz song, a guitarist will be expected to be able to play "jazz voicings" of the chords, which emphasize the third, seventh and often the sixth or ninth chord tones (this contrasts with the barre chord voicings used in pop and rock, which emphasize the root, fifth, and to a lesser degree, the third of the chord). Drummers and percussionists are expected to be able to improvise or prepare rhythm parts that suit the style of a given song. In some cases, an arranger, orchestrator or composer will provide a written-out bass part or drum part written in music notation (the five-line staff in which the notes are round symbols with or without stems). It is rare in jazz or rock for chords to be written out in music notation; the arranger or songwriter typically writes the chord symbol and expects the guitarist to improvise the appropriate chord voicing.
Other roles
Rhythm section members may be expected to sing backup vocals or harmony parts in some styles of music. In some styles of music, notably 2010s-era pop, hip hop music and funk, rhythm section members may be required to perform a rhythmic dance routine, which may range from a simple body movement to a complex dance choreography that requires significant dance skills. In some types of heavy metal music, rhythm section members (guitar, bass, drums) may be expected to be able to "headbang" (move their head in an up and down fashion in time with the beat) while performing. Less commonly, some rhythm section members may sing lead vocals (e.g., Phil Collins or Sting). In some groups, one rhythm section member may have other roles, such as bandleader (e.g., jazz bassist Charles Mingus), conductor (often the case in 2010s-era musical theatre shows), songwriter, composer or arranger.
Components
Jazz
In the case of swing bands, the classic rhythm section comprises a quartet of electric guitar, piano, double bass, and drums; a noted example is that of the Count Basie Orchestra with Freddie Green, the Count, Walter Page, and Jo Jones. Earlier jazz bands had used banjo in place of guitar, and other bass instruments such as the tuba for recording purposes prior to the advent of microphone technology in studios.
As bebop evolved, smaller jazz groups dropped the guitar, and many free jazz ensembles dropped the piano as well. Auxiliary percussion such as claves, bongos or maracas can also be used, especially in music influenced by strains from Latin America such as salsa and samba. In theory any instrument or instruments can provide a steady rhythm: for example, in the trio led by Jimmy Giuffre the late 1950s, the clarinet, valve trombone and guitar all switched between lead and supporting roles.
In the 1950s, some jazz bandleaders began to replace the double bass with the then-newly invented electric bass. However, the electric bass made a big impact on jazz in the 1970s, with the advent of jazz rock and jazz fusion. The electric bass was much easier to amplify to stadium-filling volumes using large bass speaker cabinets and amplifiers than an upright bass. The electric bass also began to be used as an expressive solo instrument, as exemplified by the performances of Jaco Pastorius and Stanley Clarke.
In the 1970s, the main chordal rhythm instruments were often electric instruments such as the Rhodes electric piano or electric clavinet, often run through effects units such as fuzz, phasers, or wah-wah pedals and amplified through loud keyboard amplifiers. The jazz fusion rhythm section followed the lead of the rock rhythm sections of the era, and used banks of speakers and powerful amplifiers to create a massive sound large enough for stadium concerts. In the later 1980s and subsequent decades, jazz fusion bands such as the Chick Corea Elektric Band used synthesizers in the rhythm section, both for chordal accompaniment and for synth bass parts.
R&B, rock and pop