Extended chord

[6] During the common practice period of Western classical music, composers orchestrating chords that are voiced in four or fewer parts would select which notes to use so as to give the desired sonority, or effect of the intended chord.

Generally, priority was given to the third, seventh and the most extended tone, as these factors most strongly influence the quality and function of the chord.

[9] Following standard voice leading rules: An important distinction between extended and added chords must be made, since the added tones and extended tones are enharmonic, but differ in function.

[14] The theory of supposition was adopted and modified by Pierre-Joseph Roussier, Friedrich Wilhelm Marpurg, and other theorists.

A. F. C. Kollmann, following Johann Kirnberger, adopted a simpler approach and one closer to that prevalent today, in which Rameau's "supposed" bass is considered the fundamental and the ninth and eleventh are regarded as transient notes inessential to the structure of the chord.

[15] In 19th-century classical music the seventh chord was generally the upper limit in "chordal consonance", with ninth and eleventh chords being used for "extra power" but invariably with one or more notes treated as appoggiaturas.

[12] The "piling up" of thirds above the tonic to make seventh, ninth, eleventh, or even thirteenth chords "is one of the most important characteristics of jazz harmony".

In these genres, chords often include added ninths, elevenths and thirteenths as well as their altered variations.

Dominant thirteenth extended chord: C–E–G–B ♭ –D–F–A play ⓘ . The upper structure or extensions, i.e. notes beyond the seventh, in red.
A thirteenth chord (E 13 ) "collapsed" into one octave results in a dissonant , seemingly secundal [ 1 ] tone cluster . Play ⓘ
Voice leading for dominant ninth chords in the common practice period. [ 10 ] Play ⓘ
Voice leading for dominant eleventh chords in the common practice period. [ 10 ] Play ⓘ
Voice leading for dominant thirteenth chords in the common practice period. [ 10 ] Play ⓘ
Fifteenth chord discussed by Marpurg as resulting from the addition of a ninth below a (dominant) seventh chord [ 11 ] Play ⓘ
Chromaticism from voice leading and borrowed and extended chords from the end of Scriabin's Preludes , Op. 48, No. 4; "though most vertical sonorities include the seventh, ninth, eleventh, and thirteenth, the basic harmonic progressions are strongly anchored to the concept of root movement by fifths." [ 16 ] Play ⓘ
A diatonic fifteenth chord on B opens Franz Liszt 's Ossa arida (1879), in, "a striking anticipation of twentieth-century harmonic experimentation". [ 17 ] Play ⓘ
Final chord of Arnold Schoenberg 's Sechs kleine Klavierstücke , 2nd movement, [ 19 ] in thirds: C–E–G–B–D ♯ –F ♯ –A ♯ –C double sharp . Play ⓘ