Extended chord in the context of "Impressionist music"

In Western music theory, a chord is a group of notes played together for their harmonic consonance or dissonance. The most basic type of chord is a triad, so called because it consists of three distinct notes: the root note along with intervals of a third and a fifth above the root note. Chords with more than three notes include added tone chords, extended chords and tone clusters, which are used in contemporary classical music, jazz, and other genres.

Chords are the building blocks of harmony and form the harmonic foundation of a piece of music. They provide the harmonic support and coloration that accompany melodies and contribute to the overall sound and mood of a musical composition. The factors, or component notes, of a chord are often sounded simultaneously but can instead be sounded consecutively, as in an arpeggio.

Musicians use various kinds of chord names and symbols in different contexts to represent musical chords. In most genres of popular music, including jazz, pop, and rock, a chord name and its corresponding symbol typically indicate one or more of the following:

• the root note (e.g. C♯)
• the chord quality (e.g. minor or lowercase m, or the symbols or + for diminished and augmented chords, respectively; chord quality is usually omitted for major chords)
• whether the chord is a triad, seventh chord, or an extended chord (e.g. )
• any altered notes (e.g. sharp five, or ♯5)
• any added tones (e.g. )
• the bass note if it is not the root (e.g. a slash chord)

For instance, the name C augmented seventh, and the corresponding symbol C, or C, are both composed of parts 1 (letter 'C'), 2 ('aug' or '+'), and 3 (digit '7'). These indicate a chord formed by the notes C–E–G–B. The three parts of the symbol (C, aug, and ) refer to the root C, the augmented (fifth) interval from C to G♯, and the (minor) seventh interval from C to B♭.

Bebop or bop is a style of jazz developed in the early to mid-1940s in the United States. It is characterized by a fast tempo, complex chord progressions—with rapid chord changes, changes of key, and substitute chords—along with virtuosic improvisation based on a combination of harmonic structure, scales, and occasional references to the melody.

Bebop developed as the younger generation of jazz musicians expanded the creative possibilities of jazz beyond the popular, dance-oriented swing music-style to a new "musician's music" that was not as danceable and demanded close listening. As bebop was not intended for dancing, it enabled the musicians to play at faster tempos. Bebop musicians explored advanced harmonies, complex syncopation, altered chords, extended chords, chord substitutions, asymmetrical phrasing, and intricate melodies. Bebop groups used rhythm sections in a way that expanded their role. Whereas the key ensemble of the swing music era was the big band of 16–18 musicians playing in an ensemble-based style, the classic bebop group was a small combo that consisted of saxophone (alto or tenor), trumpet, piano, guitar, double bass, and drums playing music in which the ensemble played a supportive role for soloists. Rather than play heavily arranged music, bebop musicians typically played the melody of a composition (called the "head") with the accompaniment of the rhythm section, followed by a section in which each of the performers improvised a solo, then returned to the melody at the end of the composition.

In music, the fifth factor of a chord is the note or pitch that is the fifth scale degree, counting the root or tonal center. When the fifth is the bass note, or lowest note, of the expressed chord, the chord is in second inversion Play.

Conventionally, the fifth is second in importance to the root, with the fifth being perfect in all primary triads (I, IV, V and i, iv, v). In jazz chords and theory however, the fifth is often omitted, or assumed, in preference for the chord quality determining third and chord extensions and additions.

An added tone chord, or added note chord, is a non-tertian chord composed of a triad and an extra "added" note. Any tone that is not a seventh factor is commonly categorized as an added tone. It can be outside the tertian sequence of ascending thirds from the root, such as the added sixth or fourth, or it can be in a chord that doesn't consist of a continuous stack of thirds, such as the added thirteenth (six thirds from the root, but the chord doesn't have the previous tertian notes – the seventh, ninth or eleventh). The concept of added tones is convenient in that all notes may be related to familiar chords.

Inversions of added tone chords where the added tone is the bass note are usually simply notated as slash chords instead of added-tone chords. For example, instead of C/D, just C/D is used.