Neapolitan chord

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In music theory, a Neapolitan chord (or simply a "Neapolitan") is a major chord built on the lowered second (supertonic) scale degree. It most commonly occurs in first inversion so that it is notated either as ♭II6 or N6 and normally referred to as a Neapolitan sixth chord.

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[edit] Origin of the name

The Neapolitan chord is so-called because it is associated with the so-called "Neapolitan school", which included Alessandro Scarlatti, Pergolesi, Paisiello, Cimarosa and other important 18th-century composers of Italian opera; but it seems to have been an established if infrequent harmonic practice by the end of the 17th century, being used by Carissimi, Corelli and Purcell. It was also a favourite idiom among composers in the Classical period, especially Beethoven, who extended its use to root-position and second-inversion chords (examples include the opening of the String Quartet op.95, the second movement of the Hammerklavier Sonata, and near the beginning and again in the recapitulation of the first movement of the Moonlight Sonata).[1]

It is known as the Neapolitan 'sixth' chord due to the interval of a sixth between the 3rd and the root note of the chord. For example, in the key of C major the Neapolitan sixth chord would consist of the notes D♭ (the root note), F (the third) and A♭ (the fifth) with the F in the bass to make it a ♭II6 or N6 rather than a ♭II. The interval of a sixth is between F and D♭.

[edit] Harmonic Function

In tonal harmony, the function of a Neapolitan chord is to prepare the dominant, substituting for the IV or ii (particularly ii6) chord. For example, it often precedes an authentic cadence, where it functions as a subdominant (IV). In such circumstances, the Neapolitan sixth may be considered to be a type of chromatic alteration of the subdominant. For example, in C major, the IV (subdominant) triad in root position contains the notes - F-A-C. By lowering the A by a semitone to A♭ and raising the C by a semitone to D♭, the Neapolitan sixth chord F-A♭-D♭ is formed. In C minor, the resemblance between the subdominant (F-A♭-C) and the Neapolitan (F-A♭-D♭) is even stronger, since only one note differs by a half-step. (Note that the Neapolitan is also only a half-step away from the diminished supertonic triad in minor in first inversion, F-A♭-D, and thus lies chromatically between the two primary subdominant function chords.)

The Neapolitan sixth chord is particularly common in minor keys. As a simple alteration of the subdominant triad (iv) of the minor mode, it provides contrast as a major chord compared to the minor subdominant or the diminished supertonic triad. The most common variation on the Neapolitan chord is the Neapolitan major seventh, which adds a major seventh to the chord (this also happens to be the tonic).

[edit] Further Harmonic Contexts

A common use of the Neapolitan chord is in tonicizations and modulations to different keys. It is the most common means of modulating down a semitone, which is usually done by using the I chord in a major key as a Neapolitan chord (or a flattened major supertonic chord in the new key, a semitone below the original).

Occasionally, a minor seventh is added to the Neapolitan chord, which turns it into a potential secondary dominant that can allow tonicization or modulation to the ♭V/♯IV key area relative to the primary tonic. For example, in C major or C minor, the Neapolitan chord with added seventh D♭7 can lead to G♭ (or F♯) major/minor. Another such use of the Neapolitan is along with the German augmented sixth chord, which can serve as a pivot chord to tonicize the Neapolitan as a tonic. In C major/minor, the German augmented sixth chord an enharmonic A♭7 chord, which could lead as a secondary dominant to D♭, the Neapolitan key area. As the dominant to ♭II, the A♭7 chord can then be respelled as a German augmented sixth, resolving back to the home key of C major/minor.

[edit] Voice Leading

Because of its close relationship to the subdominant, the Neapolitan sixth resolves to the dominant using similar voice-leading. In the present example of a C major/minor tonic, the D♭ generally moves down by step to the leading tone B-natural (creating the expressive melodic interval of a diminished third, one of the few places this interval is accepted in traditional voice-leading), while the F in the bass moves up by step to the dominant root G. The fifth of the chord (A♭) usually resolves down a semitone to G as well. In four-part harmony, the bass note F is generally doubled, and this doubled F either resolves down to D or remains as the seventh F of the G-major dominant seventh chord. In summary, the conventional resolution is for all upper voices to move down against a rising bass.

Care must be taken to avoid consecutive fifths when moving from the Neapolitan to the cadential 6/4. The simplest solution is to avoid placing the fifth of the chord in the top part. If the root or (doubled) third is in the top part, all upper parts simply resolve down by step while the bass rises. According to some theorists, however, such an unusual consecutive fifth (with both parts descending a semitone) is allowable in chromatic harmony, so long as it does not involve the lowest part. (The same allowance is often made more explicitly for the German augmented sixth, except in that case it may involve the bass – or must, if the chord is in its usual root position.)

[edit] Inversions

The flattened major supertonic chord is sometimes used in root position (in which case there may be even more concessions regarding consecutive fifths, similar to those just discussed); an example occurs in the second last bar of Chopin's Prelude in C minor, Op. 28, No. 20. In very rare cases, the chord occurs in second inversion; for example, in Handel's Messiah, in the aria Rejoice greatly.[2]

v • d • e
Chords
By Type Triad Major · Minor · Augmented · Diminished · Suspended
Seventh Major · Minor · Dominant · Diminished · Half-diminished · Minor-major · Augmented major · Augmented minor
Extended Ninth · Eleventh · Thirteenth
Other Sixth · Augmented sixth · Altered · Added tone · Polychord · Quartal and quintal · Tone cluster · Power
By Function Diatonic Tonic · Dominant · Subdominant · Submediant
Altered Borrowed · Neapolitan chord · Secondary dominant
With Names Elektra chord · Hendrix chord · Mystic chord · Petrushka chord · Tristan chord · So What chord

[edit] Notes

  1. ^ William Drabkin: 'Neapolitan sixth chord', Grove Music Online ed. L. Macy (Accessed 8 June 2007), <http://www.grovemusic.com>
  2. ^ Christ, W, DeLone, R, Kliewer, V, Rowell, L, and Thomson, W, Materials and structure of music, volume 2, 2nd edition 1973, Prentice Hall, NJ, pp. 146–7.