Anonchord tone (NCT),nonharmonic tone, orembellishing tone is anote in a piece ofmusic orsong that is not part of the implied or expressedchord set out by theharmonic framework. In contrast, achord tone is a note that is a part of thefunctional chord. Nonchord tones are most often discussed in the context of thecommon practice period ofclassical music, but the term can also be used in the analysis of other types oftonal music, such as Westernpopular music.
Nonchord tones are often categorized asaccented non-chord tones andunaccented non-chord tones depending on whether the dissonance occurs on an accented or unaccentedbeat (or part of a beat).
Over time, some musical styles assimilated chord types outside of the common-practice style. In these chords, tones that might normally be considered nonchord tones are viewed as chord tones, such as the seventh of aminor seventh chord. For example, in 1940s-erabebop jazz, an F♯ played with a C 7 chord would be considered a chord tone if the chord were analyzed as C7(♯11). In European classical music, "[t]he greater use of dissonance from period to period as a result of the dialectic of linear/vertical forces led to gradual normalization ofninth,eleventh, andthirteenth chords [in analysis and theory]; each additional non-chord tone above the foundational triad became frozen into the chordal mass."[2]
Chord and nonchord tones are defined by their membership (or lack of membership) in a chord: "The pitches which make up a chord are calledchord-tones: any other pitches are callednon-chord-tones."[3] They are also defined by the time at which they sound: "Nonharmonic tones are pitches that sound along with a chord but are not chord pitches."[4] For example, if an excerpt from a piece of music implies or uses a C-major chord, then the notes C, E and G are members of that chord, while any other note played at that time (e.g., notes such as F♯) is a nonchord tone. Such tones are most obvious inhomophonic music but occur at least as frequently incontrapuntal music.
According toMusic in Theory and Practice, "Most nonharmonic tones aredissonant and createintervals of a second, fourth or seventh",[4] which are required toresolve to a chord tone in conventional ways. If the note fails to resolve until the next change of harmony, it may instead create aseventh chord orextended chord. While theoretically in a three-note chord, there are nine possible nonchord tones inequal temperament, in practice nonchord tones are usually in the prevailingkey. Augmented and diminished intervals are also considered dissonant, and all nonharmonic tones are measured from thebass note, or lowest note sounding in the chord except in the case of nonharmonic bass tones.[4]
Nonharmonic tones generally occur in a pattern of three pitches, of which the nonharmonic tone is the center:[4]
| Chord tone | – | Nonchord tone | – | Chord tone |
| Preparation | – | Dissonance | – | Resolution |
Nonchord tones are categorized by how they are used. The most important distinction is whether they occur on a strong or weakbeat and are thus either accented or unaccented nonchord tones.[4] They are also distinguished by their direction of approach and departure and the voice or voices in which they occur and the number of notes they contain.
Ananticipation (ANT) occurs when this note is approached bystep and then remains the same. It is basically a note of the second chord played early. In the example below, the dissonant B in bar 1 is approached by step and resolves when that same pitch becomes a chord tone in bar 2.
Aportamento is the late Renaissance precursor to theanticipation,[5] though today it refers to aglissando.
Aneighbor tone (NT) orauxiliary note (AUX) is a nonchord tone that passes stepwise from a chord tone directly above or below it (which frequently causes the NT to create dissonance with the chord) and resolves to the same chord tone:
In practice and analysis, neighboring tones are sometimes 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 anupper neighboring tone or anupper auxiliary note while a neighboring tone that is a step lower than the surrounding chord tones is alower neighboring tone orlower auxiliary note. However, followingHeinrich Schenker's usage inFree Composition, some authors reserve the term "neighbor note" to the lower neighbor ahalf step below the main note.[6]
The German termNebennote is a somewhat broader category, including all nonchord tones approached from the main note by step.[6]
Anescape tone (ET) orechappée is a particular type of unaccented incomplete neighbor tone that is approached stepwise from a chord tone and resolved by a skip in the opposite direction back to the harmony.
Apassing tone (PT) orpassing note is a nonchord tone prepared by a chord tone a step above or below it and resolved by continuing in the same direction stepwise to the next chord tone (which is either part of the same chord or of the next chord in the harmonic progression).
Where two nonchord tones are before the resolution they aredouble passing tones ordouble passing notes.
A tone that sits between two chord tones and is between them.
A neighbour tone is where there is a step up or down from a note (or chord tone) and then move back to the original note.[7]
Endeavor, moreover, to introduce suspensions now in this voice, now in that, for it is incredible how much grace the melody acquires by this means. And every note which has a special function is rendered audible thereby.
— Johann Joseph Fux (1725)[8]
Asuspension (SUS) (sometimes referred to as asyncope)[9] occurs when the harmony shifts from one chord to another, but one or more notes of the first chord (the preparation) are either temporarily held over into or are played again against the following chord (against which they are nonchord tones called thesuspension) before resolving downwards to a chord tone by step (the resolution). The whole process is called asuspension as well as the specific nonchord tone(s).
Suspensions may be further described with two numbers: (1) theinterval between the suspended note and thebass note and (2) the interval between the resolution and the bass note. The most common suspensions are 4–3 suspension, 7–6 suspension, or 9–8 suspension. Note that except for the 9–8 suspensions, the numbers are typically referred to using thesimple intervals, so for instance, if the intervals are actually an 11th and a 10th (the first example below), one would typically call it a4–3 suspension. If the bass note is suspended, then the interval is calculated between the bass and the part that is most dissonant with it, often resulting in a 2–3 suspension.[10]
Suspensions must resolve downwards. If a tied note is prepared like a suspension but resolves upwards, it is called aretardation. Common retardations include 2–3 and 7–8 retardations.
Decorated suspensions are common and consist ofportamentos or double eighth notes, the second being a lower neighbor tone.
A chain of suspensions constitutes the fourth species ofcounterpoint; an example may be found in the second movement of Corelli'sChristmas Concerto.
Anappoggiatura (APP) is a type of accented incomplete neighbor tone approached skip-wise from one chord tone and resolved stepwise to another chord tone ("overshooting" the chord tone).
Nonharmonic bass notes are bass notes that are not a member of the chord below which they are written. Examples include theElektra chord.[11] An example of a nonharmonic bass from the third movement of Stravinsky'sSymphony of Psalms.[12]
Changing tones (CT) are two successive nonharmonic tones. A chord tone steps to a nonchord tone which skips to another nonchord tone which leads by step to a chord tone, often the same chord tone. They may imply neighboring tones with a missing or implied note in the middle. Also calleddouble neighboring tones orneighbor group.[4]
Another form of nonchord tone is apedal point orpedal tone (PD) ornote, almost always thetonic ordominant, which is held through a series of chord changes. The pedal point is almost always in the lowest voice (the term originates fromorgan playing), but it may be in an upper voice; then it may be called aninverted pedal. It may also be between the upper and lower voices, in which case it is called aninternal pedal.
Achromatic nonharmonic tone is a nonharmonic tone that ischromatic, or outside of thekey and createshalf-step motion. The use of which, especiallychromatic appoggiaturas andchromatic passing tones, increased in theRomantic Period.[13] The example below shows chromatic nonharmonic tones (in red) in the first four measures of Chopin'sPrelude No. 21, op. 28.[13]
Sources
Media related toNonchord tones at Wikimedia Commons | ||
| Perfect Consonances | ||
| Imperfect Consonances | ||
| Dissonances | ||
![{
\new PianoStaff <<
\new Staff <<
\new Voice \relative c'' {
\tempo "Cantabile"
\clef treble \key bes \major \time 3/4
\override DynamicLineSpanner.staff-padding = #2.5
f2.\p( d2 \acciaccatura { f8 } es4 d2. g,2.)
}
>>
\new Staff <<
\new Voice \relative c {
\clef bass \key bes \major \time 3/4
\override NoteHead.color = #red \hide Stem s4 e8 s4.
s4 e8 s4.
s4 fis8 b s4
s4 fis8 b s4
}
\new Voice \relative c, {
\clef bass \key bes \major \time 3/4
bes8\<\sustainOn_[ f''^( <e g>\sustainOff <es a> <d bes'> <c c'>]\!
bes8\<\sustainOn_[) <f' d'>^( <e g>\sustainOff <es a> <d bes'> bes]\!
es,8\<\sustainOn_[) g'^( <fis a>\sustainOff <f b> <es c'> <d d'>]\!
c8\<\sustainOn_[) <g' es'>^( <fis a>\sustainOff <f b> <es c'> <c es'>])\!
}
>>
>> }](/image.pl?url=http%3a%2f%2fen.wikipedia.org%2f%2fupload.wikimedia.org%2fscore%2ft%2fc%2ftcjekb1ivlqux7kmvgn3ndd0od59g6c%2ftcjekb1i.png&f=jpg&w=240)