Mixed-interval chord

In music a mixed-interval chord is a chord not characterized by one consistent interval. Chords characterized by one consistent interval, or primarily but with alterations, are equal-interval chords. Mixed interval chords "lend themselves particularly" to atonal music since they tend to be dissonant.^[2]

Equal-interval chords are often of indeterminate root and mixed-interval chords are also often best characterized by their interval content.^[2] "Equal-interval chords are often altered to make them 'impure' as in the case of quartal and quintal chords with tritones, chords based on seconds with varying intervals between the seconds."^[2]

References

^ Reisberg, Horace (1975). "The Vertical Dimension in Twentieth Century Music", p.371, Aspects of Twentieth-Century Music, chap. 5, p.362-72. Wittlich, Gary (ed.). Englewood Cliffs, New Jersey: Prentice-Hall. ISBN 0-13-049346-5.
^ ^a ^b ^c Reisberg (1975), p.362.

Chords

By form

Triad	Major Minor Augmented Diminished Suspended
Seventh	Leading-tone Major Minor Dominant Dominant seventh flat five Diminished Half-diminished Diminished major Minor-major Augmented major Augmented minor Altered seventh Nondominant Harmonic seventh
Extended	Ninth Eleventh Thirteenth Upper structure Dominant 7♯9 Polychord Tone cluster
Added / omitted	Sixth Augmented sixth Lydian Seven six
Specific	Alpha Bridge Complexe sonore Dream Elektra Farben Grandmother Magic Mystic Northern lights Petrushka Psalms So What Tristan Viennese trichord
General	Mixed interval Secundal Tertian Quartal Synthetic chord Tetrad

By function

Diatonic	Tonic Supertonic Mediant Subdominant Dominant Submediant Leading-tone / Subtonic
Altered	Approach Borrowed Chromatic mediant Neapolitan Passing
Secondary	Secondary dominant Secondary leading-tone Secondary supertonic
Other	Common Contrast Primary triad Subsidiary Substitute