Avoid note

In jazz theory, an avoid note is a scale degree which is considered especially dissonant relative to the harmony implied by the root chord, and is thus better avoided.

In major-key tonality the avoid note is the fourth diatonic scale step, or 11th, which is a minor ninth above the 3rd of the chord, and thus very harsh.^[1] In melody it is usually avoided, treated as a "scale approach note"^[2] or passing note,^[3] or sharpened. It is not available in harmony. The available tensions for a dominant seventh chord are 9, ♯11, and 13.^[1]

In minor harmony the sixth scale step is usually avoided, and the 13th is not regarded as an available tension.^[2]

In modal terms, the available scale steps of the mode (or available tensions for the chords) of the diatonic scale steps are those a whole step above the chord tones, and the avoid notes are those that are not. The only exception is the Dorian mode of the second scale degree, where the sixth is avoided although it is a whole step above the fifth; this is because the tritone between this and the third scale step would give an unwanted dominant quality.^[2] Taking C major as an example, the avoid notes are:^[2]

Avoid notes for modes of the C major scale

Scale degree	Chord	Mode	Avoid note	Available tensions
1	Cmaj7	Ionian	Fourth scale step, F	9, 13
2	Dm7	Dorian	Sixth scale step, B	9, 11
3	Em7	Phrygian	Second and sixth scale steps, F and C	11
4	Fmaj7	Lydian	No avoid note	9, ♯11, 13
5	G7	Mixolydian	Fourth scale step, C	9, 13
6	Am7	Aeolian	Sixth scale step, F	9, 11
7	Bø7	Locrian	Second scale step, C	11, ♭13

In his modal approach to minor harmony Haerle^[4] does not use the term avoid note, but discusses "intolerably dissonant" notes and how they should be resolved. For the melodic minor scale he gives these:

Avoid notes for modes of the melodic minor scale

Scale degree	Chord	Mode	Avoid note	Available tensions
1	Cmmaj7	Ionian, ♭3	No avoid note	9, 11, 13
2	Dm7	Dorian, ♭2	Second scale step, E♭	11, 13
3	E♭+maj7	Lydian augmented	Sixth scale step, C	9, ♯11
4	F7	Lydian, ♭7	No avoid note	9, ♯11, 13
5	G7	Mixolydian, ♭6	Either the fifth or sixth scale step, D or E♭	9, 11
6	Aø7	Locrian, ♯2	No avoid note	9, 11, ♭13
7	Bø7	Super-Locrian	No avoid note	(usually played as altered dominant)

See also

• Eleventh chord
• Thirteenth chord
• Tritone
• Chord-scale system

References

1. Nettles, Barrie (1987). Harmony 1. Berklee College of Music. p. 34-35.
2. Nettles, Barrie (1987). Harmony 3. Berklee College of Music. pp. 15–17.
3. Humphries, Carl (2002). The Piano Handbook (1st ed.). San Francisco: Freeman: Backbeat Books. p. 128. ISBN 0-87930-727-7.
4. Haerle, Dan (1980). The Jazz Language: A Theory Text for Jazz Composition and Improvisation. Miami, Florida: Studio 224. ISBN 978-0-7604-0014-2.