In jazz music, the lydian chord is the major 7♯11 chord, or ♯11 chord, the chord built on the first degree of the lydian mode, the sharp eleventh being a compound augmented fourth. It is described as "beautiful" and "modern sounding." The 7♯11 chord generally resolves down by a half step while the enharmonically equivalent 7♭5 generally resolves up a fourth to the tonic being a dominant chord (♯11=♯4=♭5, see octave equivalency).
In a chord chart the notation, "Lydian" indicates a major family chord with an added augmented eleventh, including maj7♯11, add9♯11, and 6♯11.
- r, 3, 5, 7, (9), ♯11, (6)
- The Lydian chord has a peculiarity, in that placing the root both above and below the augmented eleventh creates an unpleasant dissonance of a tritone.
- The interval of the sixth is used even though it is described after other compound intervals, and perhaps should also be a compound interval (i.e., thirteenth).[vague] However, convention in Jazz dictates that when describing the major sixth, the simple interval, i.e., 6 is almost invariably used instead of the compound interval, i.e., 13. This helps avoid confusion with the dominant thirteenth.[vague] However, this trend has been almost reversed in more recent evolutions of jazz.[clarification needed]
The dominant 7♯11 or Lydian dominant (C7♯11) comprises the notes:
- r, 3, (5), ♭7, (9), ♯11, (13)
Basing this chord on the pitch C results in the pitches:
- C, E, G, B♭, (D), F♯, (A)
The same chord type may also be voiced:
- C, E, B♭, F♯, A, D, F♯
This voicing omits the perfect fifth (G) and raises the major ninth (D) by an octave. The augmented eleventh (F♯) is also played twice in two different registers. This is known as "doubling".
- Juergensen, Chris (2006). The Infinite Guitar, p.50. ISBN 1-4116-9007-9.
- Juergensen (2006), p.51.
- Munro, Doug (2002). Jazz Guitar: Bebop and Beyond, p.39. ISBN 978-0-7579-8281-1.
- Miller, Scott (2002). Mel Bay Getting Into Jazz Fusion Guitar, p.44. ISBN 0-7866-6248-4.
- Benward & Saker (2009). Music in Theory and Practice: Volume II, p.185. Eighth Edition. ISBN 978-0-07-310188-0.