Comping

Comping (an abbreviation of accompanying; or possibly from the verb, to "complement") is a term used in jazz music to describe the chords, rhythms, and countermelodies that keyboard players (piano or organ), guitar players, or drummers use to support a jazz musician's improvised solo or melody lines. The term is also used for the action of accompanying, and for left hand part of a solo pianist.

In a standard jazz combo, the pianist or guitarist typically comps during the horn and double bass solos by improvising chords and countermelodies.

The chordal accompaniment used in jazz is different from the chordal accompaniment style used in many types of popular music, such as rock and folk.

In combos with a guitar player, the guitar player usually comps for soloists. If there is both a pianist and a guitarist, as sometimes occurs in organ trios or big bands, they may either alternate comping or comp at the same time. Having two chordal instruments comp at the same time is difficult to do well. The two compers may make different, clashing interpretations of the same chord (e.g., the pianist may add a flat 13th, while the guitarist plays a natural 13th), or the texture may become overly cluttered.

During swing-feel songs, drummers will usually comp with one hand on the snare drum while playing time on the cymbals, typically on the ride cymbal (see drum kit). More skilled drummers often comp with even all three limbs excluding their right-hand ride pattern (snare drum, bass drum, hi-hats). They will most likely develop the simple jazz drum pattern and add a few "bomb" bass drum notes for extra effect. In small jazz ensembles ("combos") with more unusual instrumentation, horn players (e.g., saxophone, trumpet, etc.) can comp by playing the melody line in the background, or by playing a sequence of notes called "guide tones" which outline the harmonic framework. Guide tones are usually the 3rd, 7th, or 9th notes of a given chord. Guide tone lines are constructed by descending through the guide tones of the chart, normally by semitone. For instance, in a duo for saxophone and bass, the saxophonist might comp during the bass solo by playing guide tones.

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