Nonchord tone
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A nonchord tone, nonharmonic tone, or non-harmony note is a note in a piece of music which is not a part of the chord that is formed by the other notes sounding at the time. Nonchord tones are most often discussed in the context of music of the common practice period, but can be used in analysis of other types of tonal music as well.
For example, if a piece of music is currently on a C Major chord, the notes CEG are members of that chord, while any other note played at that time is a nonchord tone. While such tones are most obvious in homophonic music, they can occur in contrapuntal music as well.
A nonchord tone is a dissonance and is required to resolve to a chord tone in conventional ways. If the note fails to resolve until the next change of harmony, it may instead create a seventh chord or extended chord. While it is theoretically possible that for a three-note chord there are (in equal temperament) nine possible nonchord tones, nonchord tones are usually in the prevailing key.
The following list is not exhaustive, but identifies the most common types of nonchord tones.
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[edit] Anticipation
- An anticipation occurs when a note is played before the chord to which the note belongs and resolves when the "anticipated" chord is reached:
[edit] Neighbor tone
- A neighbor tone or auxiliary note is a nonchord tone which is preceded by a chord tone directly above or below it and resolves to the same tone:
In practice and analysis, neighboring tones are often differentiated depending upon whether or not they are lower or higher than the chord tones surrounding them. A neighboring tone that is a step higher than the surrounding chord tones is called an upper neighboring tone or an upper auxiliary tone whereas a neighboring tone that is a step lower than the surrounding chord tones is a lower neighboring tone or lower auxiliary tone.
[edit] Passing tone
- A passing tone or passing note is the nonchord tone of a part which had started at one chord tone and moved up or down through one or more nonchord tones and resolved to another chord tone (possibly of another chord, often of the same chord). It can also be a non-chord note between two common tones (tones that are the same side by side):
[edit] Suspension
- A suspension occurs when the harmony shifts from one chord to another, but one or more notes of the first chord are temporarily held over into the second in which they are nonchord tones before resolving to a chord tone:
Suspensions may be further described using the number of the interval forming the suspension and its resolution; e.g. 4-3 suspension, 7-6 suspension. Most suspensions resolve downwards; the example shown above, a 7-8 suspension, is a rare example of an upwards resolution (also called a retardation). A suspension must be prepared with the same note (in the same voice) using a chord tone in the preceding chord; otherwise it is an appoggiatura. The notes are often tied, but this is optional.
A suspended chord is an added tone chord with a "suspended" fourth or second as an added tone which doesn't resolve.
- For an audiovisual illustration of the concept of harmonic suspension, visit external link suspension and pedal point.
[edit] Escape tone
- An escape tone is a movement by step in the opposite direction of the harmonic motion in that voice and is resolved by leap in the direction of harmonic motion:
Appoggiatura are sometimes used to provide this function.
[edit] Pedal point
Another form of nonchord tone is a pedal point or pedal tone or note, almost always the tonic or dominant, which is held through a series of chord changes. The pedal point is almost always in the lowest voice (the term originates from organ playing), but it may be in an upper voice; then it may be called an inverted pedal. It may also be between the upper and lower voices, in which case it is called an internal pedal.
