Неаккордовые тоны в музыке

Type of musical note

A nonchord tone (NCT), nonharmonic tone, or embellishing tone is a note in a piece of music or song that is not part of the implied or expressed chord set out by the harmonic framework. In contrast, a chord tone is a note that is a part of the functional chord. Non chord tones are most often discussed in the context of the common practice period of classical music, but they can be used in the analysis of other types of tonal music as well, such as Western popular music. Nonchord tones are often categorized as accented non chord tones and unaccented non chord tones depending on whether the dissonance occurs on an accented or unaccented beat (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 a minor seventh chord. For example, in 1940s era bebop jazz, an F played with a C 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 of ninth, eleventh, and thirteenth chords [in analysis and theory]; each additional non chord tone above the foundational triad became frozen into the chordal mass."

Chord and nonchord tones are defined by their membership (or lack of membership) in a chord: "The pitches which make up a chord are called chord tones: any other pitches are called non chord tones." 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." 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 in homophonic music but occur at least as frequently in contrapuntal music. According to Music in Theory and Practice, "Most nonharmonic tones are dissonant and create intervals of a second, fourth or seventh", though today it refers to a glissando.

A suspension (SUS) (sometimes referred to as a syncope) 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 second chord (against which they are nonchord tones called the suspension) before resolving downwards to a chord tone by step (the resolution). The whole process is called a suspension as well as the specific nonchord tone(s). Suspensions may be further described with two numbers: (1) the interval between the suspended note and the bass 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 the simple intervals, so for instance, if the intervals are actually an 11th and a 10th (the first example below), one would typically call it a 4–3 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. Suspensions must resolve downwards. If a tied note is prepared like a suspension but resolves upwards, it is called a retardation. Common retardations include 2–3 and 7–8 retardations. Decorated suspensions are common and consist of portamentos or double eighth notes, the second being a lower neighbor tone. A chain of suspensions constitutes the fourth species of counterpoint; an example may be found in the second movement of Arcangelo Corelli's Christmas Concerto.

An appoggiatura (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 the Elektra chord. An example of a nonharmonic bass from the third movement of Stravinsky's Symphony of Psalms.

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 called double neighboring tones or neighbor group. The example below shows chromatic nonharmonic tones (in red) in the first four measures of Frédéric Chopin's Prelude No. 21, op. 28.