In a musical composition, a chord progression or harmonic progression (informally chord changes, used as a plural) is a succession of chords. Chord progressions are the foundation of harmony in Western musical tradition from the common practice era of Classical music to the 21st century. Chord progressions are the foundation of popular music styles (e.g., pop music, rock music), traditional music, as well as genres such as blues and jazz. In these genres, chord progressions are the defining feature on which melody and rhythm are built.
A chord may be built upon any note of a musical scale. Therefore, a seven-note diatonic scale allows seven basic diatonic triads, each degree of the scale becoming the root of its own chord. A chord built upon the note E is an E chord of some type (major, minor, diminished, etc.) Chords in a progression may also have more than three notes, such as in the case of a seventh chord (V7 is particularly common) or an extended chord. The harmonic function of any particular chord depends on the context of the particular chord progression in which it is found.
Diatonic scales such as the major and minor scales lend themselves particularly well to the construction of common chords because they contain many perfect fifths. Such scales predominate in those regions where harmony is an essential part of music, as, for example, in the common practice period of western classical music. In considering Arab and Indian music, where diatonic scales are used, there are also available a number of non-diatonic scales, the music has no chord changes, remaining always upon the key-chord, an attribute which has also been observed in hard rock, hip hop, funk, disco, jazz, etc.
Three-chord progressions provide the harmonic foundation of much African and American popular music, and they occur sectionally in many pieces of classical music (such as the opening bars of Beethoven's Pastoral Symphony).
This progression had been in use from the earliest days of classical music and then generated popular hits such as Rodgers and Hart's "Blue Moon" (1934) and Hoagy Carmichael's "Heart and Soul" (1938).
... during 1960s some pop groups started to experiment with modal chord progressions as an alternative way of harmonizing blues melodies. ... This created a new system of harmony that has influenced subsequent popular music.
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 term is common in modern small musical ensembles, such as bands that play jazz, 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.
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.). The term rhythm section may also refer to the instruments in this group (named collectively the "rhythm section instruments").
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.
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.
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.
The drums and bass both supply a rhythmic pulse for the music, and the bass instrument supplies a harmonic foundation with a bassline. The types of basslines performed by the bass guitarist vary widely from one style of music to another. Despite all of the differences in the styles of bassline in most styles of popular music, the bass guitarist fulfills a similar role: anchoring the harmonic framework (often by emphasizing the roots of the chord progression) and laying down the beat (in collaboration with the drummer). The importance of the bass guitarist and the bass line varies in different styles of music. In some pop styles, such as 1980s-era pop and musical theater, the bass sometimes plays a relatively simple part, and the music forefronts the vocals and melody instruments. In contrast, in reggae or funk, entire songs may be centered around the bass groove, and the bassline is very prominent in the mix.
Similarly, the role of the drummer varies a great deal from one style of music to another. In some types of music, such as traditional 1950s-style country music, the drummer has a rudimentary "timekeeping" role, and the drums are placed low in the mix by the sound engineers. In styles such as progressive rock, metal, and jazz fusion, the drummers often perform complex, challenging parts, and the drums may be given a prominent placement in the mix; as well, the drummer may be often given prominent solo breaks, fills, or introductions that put the spotlight on their technical skills and musicality. In the more experimental forms of free jazz and jazz fusion, the drummer may not play the strict "timekeeping" role that is associated with drums in pop music. Instead, the drums may be used more to create textured polyrhythmic soundscapes. In this type of situation, the main pulse is often provided by the bass player rather than the drummer. 2b1af7f3a8