"Bichord" redirects here. For a one string instrument, see Monochord. For an instrument with two or more strings per note, see Course (music).
In music and music theory, a polychord consists of two or more chords, one on top of the other.[2][3][4] In shorthand they are written with the top chord above a line and the bottom chord below,[5] for example F upon C: F/C.
In the polychords in the image above, the first might suggest a thirteenth chord, the second may suggest a D minor ninth chord with upper extensions, but the octave separation of the 3rd makes the suggestion of two independent triads a minor ninth apart even more likely, and the fourth is a split-third chord.[7]
Extended chords contain more than one triad, and so can be regarded as a type of polychord:
For example G7♯11♭9 (G–B–D–F–A♭–C♯) is formed from G major (G–B–D) and D♭ major (D♭–F–A♭), or D♭/G.[5] (C♯ ≡ D♭)
The Lydian augmented scale, "has a polychord sound built in,"[9] created by superimposing the Caug and the E (Playⓘ) and/or F♯dim (Playⓘ) triads that exist in the scale, this being, "a very common practice for most bop and post-bop players [such as McCoy Tyner]."[10]
Examples of extended chords include the Elektra chord.
When one or both of the chords in a polychord are not "chords" in some exclusive sense according to some preferred chord theory or other, polychords devolves into chordioid technique.
^Haerle, Dan (1982). The Jazz Language: A Theory Text for Jazz Composition and Improvisation, p. 30. ISBN978-0-7604-0014-2. "The term polychord literally means many (poly) chords. In actual practice, a polychord is usually a combination of only two chords which creates a more complex sound."
^Guy Capuzzo, Tom Dempsey (2006). Theory for the Contemporary Guitarist, p. 76. ISBN978-0-7390-3838-3. "A bichord (other-wise known as a polychord) consists of two triads played together."
^Edward Shanaphy, Joseph Knowlton (1990). The Do It Yourself Handbook for Keyboard Playing, p. 62. ISBN978-0-943748-00-9. "A polychord is nothing more than the playing of two chords at the same time."
^ abPolicastro, Michael A. (1999). Understanding How to Build Guitar Chords and Arpeggios, p. 168. ISBN978-0-7866-4443-8.
^Reisberg, Horace (1975). "The Vertical Dimension in Twentieth Century Music", Aspects of Twentieth-Century Music, p. 336. Wittlich, Gary (ed.). Englewood Cliffs, New Jersey: Prentice-Hall. ISBN0-13-049346-5.
^ abKostka & Payne (1995). Tonal Harmony, p. 494. Third Edition. ISBN0-07-035874-5.
^Marquis, G. Welton (1964). Twentieth Century Music Idioms. Englewood Cliffs, New Jersey: Prentice-Hall, Inc.
^Walter Everett (Autumn, 2004). "A Royal Scam: The Abstruse and Ironic Bop-Rock Harmony of Steely Dan", pp. 208–09, Music Theory Spectrum, Vol. 26, No. 2, pp. 201–35.