Twin Sons from Different Mothers: Harmonic Convergence in Jazz and Classical Music, Part 4: "The Neapolitan 6th Chord in Jazz and Classical Music"

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IV: The Neapolitan 6th Chord in Classical Music and Jazz

The "Neapolitan 6th" chord (N6) is another sonority whose definition is based on the triad that it makes, which is a vertical perspective that glosses over its actual horizontal function. It is described in theory texts as the chord on the lowered supertonic (scale degree 2) in first inversion. Thus, in the key of C minor (the N6 is generally a minor key phenomenon), the N6 is a D♭ major chord in first inversion, i.e., with F in the bass:



The N6, however, has a subdominant function, which is evident from its position preceding the dominant or tonic chord, and also because the bass note (F) is doubled, which is not the case for other chords in first inversion, which double the root of the chord (D♭). Theorists were undoubtedly aware of its function as a subdominant from early on, as seen in examples 328 and 331from William Crotch's work "Elements of Musical Composition" from 1812:



When encountering these chords in music theory classes, students often ask where the names came from—Crotch says: These [German, French, and Italian Augmented 6th Chords] and the Neapolitan sixes [sic] are denominated after the nations which invented them (Crotch 71). Crotch also states that The Neapolitan sixth is a minor third and a minor sixth to Fa, and is never inverted (Crotch 72). While generally true, over time, this "rule" would be broken—we will see that, among others, Frederic Chopin, Miles Davis and Bill Evans had no issues inverting the N6.

Here Crotch explicitly states that the chord is "fa" (IV) that moves to "sol" (V) or to "do" (I or i), so they clearly thought of the chord in its linear function rather than as a triad on ♭II in first inversion.

Why not label it as the subdominant with a lowered 6th instead of as ♭II in first inversion? The former description is awkward because the chord has no fifth, while the latter is easier because it uses the well-known triad as its pneumonic. Thus, labeling it as ♭II in first inversion is pedagogically convenient—it is easy to spell and remember.

In Part 3, where we looked at +6 chords, we noted that, in the case of +6 chords, they approached the dominant from a half step above (upper leading tone) and a half step below (leading tone). There is a similar phenomenon at play in the N6. However, unlike the simultaneous vertical sonority in the +6, it occurs horizontally as a result of voice leading:



Interesting to note here is that the N6 moves to the dominant, and the distance from ♭II to V is a tritone. So, while not a tritone sub like the +6, there is, nonetheless, some conspicuous tritone activity here.



In the N6 chord, the tonic is approached horizontally from its leading tone and its upper leading tone, which creates the signature foreboding and unsettling character of Phrygian mode.

Like the +6, the N6 regularly moves to the dominant with the interpolation of the tonic in second inversion:





Here is an example of the N6 from the second movement, "Summer," of Antonio Vivaldi's most famous piece, "The Four Seasons." The N6 occurs at 11:18 and then again at 11:30, an octave lower.



This example is from the Second Movement of Mozart's Piano Concerto #23 in A major, where the N6 occurs at 0:44.

One of the most well-known examples occurs in Beethoven's "Moonlight Sonata" at 0:23.



As with the +6 chords, composers took advantage of N6 chords to use them as pivot chords to modulate to other keys. Here is Schubert's "Impromptu in G♭ major, op 90 #3." The piece moves from G♭ major to E♭ minor. From E♭ minor, Schubert uses the N6 (F♭) at 1:51 as a pivot chord to modulate to C♭ major, where F♭ is IV.



Listen for the delightful sleight of hand as the N6 appears and sets up an expected move to V, but instead it moves to C♭ in second inversion. The F♭ root follows in the bass, but it is no longer the N6, it is now the 7th of the dominant chord in C♭and has thus been transformed and thoroughly domesticated —it is now a friendly dominant moving to its tonic in first inversion!



So far, these examples have all used the N6 in first inversion as Crotch indicated. However, by 1839, in his "Prelude in C Minor, op. 28 #20," composers like Chopin felt free to use the chord in root position instead of first inversion. The Neapolitan in root position (N, not N6) is heard at 1:06.





The N6 is not found with any regularity in popular music, likely due to its Phrygian implications, a mode that is dark and ominous. With those characteristics, Phrygian is thus well suited to hard rock/metal genres, whose musical and lyrical content is often dark and ominous. While we do not find the Phrygian mode in the Billboard charts, it can, in certain circumstances, find considerable success. The wildly successful German metal band Rammstein performs "Engel," featuring Phrygian mode on D in the verse. (Interestingly, the intro to the tune features two different modes sounding simultaneously: D Phrygian and A Aeolian. This is exceedingly rare in the rock genre, even more so given that Rammstein can easily fill 20,000-seat stadiums.)



There is a conspicuous example of it being used in a big pop music hit—it is found in Barry Manilow's "Could It Be Magic" from 1975. Not only is the N6 found in the following video, but so is the entire chord progression from Chopin's prelude. Manilow plays the prelude before performing the song inspired by it.

Neapolitan 6th Chords in Jazz

We have seen how the N6 is used in classical music—it dramatizes the movement to the dominant and the tonic. It does this by utilizing the upper leading tone and the leading tone of the tonic, the former of which imbues the cadence with the somewhat ominous connotations of Phrygian mode.





In jazz, it is rare for the N6 to be found moving similarly, i.e., N6—>V—>i. Here it is in Jerome Kern's "All The Things You Are," which was discussed in Part 3 partially because of its use of the +6 chord as a pivot chord in an enharmonic modulation. Here we find Kern using the same modulation device as we saw earlier in the Schubert Impromptu—D♭ major7 is IVmaj7 in A♭ and it is the Neapolitan in root position in C major, so it functions as a pivot chord. This repeats a perfect fifth up in the second phrase where the same modulation happens in E♭—A♭ major7 in E♭ is IVmaj7 and it is the Neapolitan in root position in G major.

In this piece alone, the classical influences are strong:

• Neapolitan chords used as pivot chords (as in the Schubert example above, and the Beethoven example from Part 3),
• Neapolitan chords used in root position (as in the Chopin example),
• Augmented 6th chord as a pivot chord,
• key relationships that are chromatic mediants, and
• The cleverly hidden "code" that spells the tonic chord in the first four key areas in the correct order.

Here is another example from "Nardis" which was written by Miles Davis in 1958, but he never recorded. It became a staple of Bill Evans' trio and solo work, so much so that he is likely the artist most associated with the tune.



Here is the A section of Nardis, where we find the Neapolitan in root position moving to the dominant, just as it does in classical music. The Neapolitan plays a very prominent role here. Along with the exotic uses of the "Spanish Phrygian," with its augmented 2nd from the harmonic minor scale, the A section has a strong Phrygian flavor, which lends to its dark and brooding character.



Finally, here is Johnny Green's "Body and Soul," written in 1930, which was previously discussed in both Part 2 and Part 3. The A section is in D♭ major and takes a radical turn to a faraway key (from five flats to two sharps) in the first four measures of the B section. We find a stunning key change at 1:24 that occurs at the end of the A section and catapults the tune into D major. The effect brightens the piece so powerfully—like clouds suddenly parting, briefly basking us in warm sunlight before the clouds quickly roll in again at the end of the B section.



However, it is not just the Neapolitan that we find—we also find the key of C major, whose tonic is the leading tone in D♭ major! We thus have the very same chromatic encirclement of the tonic by the upper leading tone and the leading tone that occurs melodically in the N6, happening at a structural level in the key centers of the bridge. (Readers will also remember that this is the engine of the Augmented Sixth where we find the upper leading tone and the leading tone of the dominant.)

As before, this has its roots in the music of the Romantic composers of the 1800s, who reveled in moving to distant key areas that were used to such great effect to define their emotionally charged music—jazz musicians and composers accessed the same devices for the same reasons. We should not be surprised, however, given the pedigree of these composers. Johnny Green and Jerome Kern, the composers of two of the most iconic jazz standards of all time—"Body and Soul" and "All The Things You Are," respectively—were professional-level pianists and composers, who studied music theory and composition at the highest levels. As such, they were well aware of classical music and its harmony, melodies, forms, and theoretical frameworks. They were the artistic descendants of Schubert, Schumann and Chopin, living in a new century full of untapped artistic potential, who drew from that rich classical well to create songs that were tightly wrought masterpieces, steeped in the classical tradition (the Romantic era in particular) as this analysis shows. Yet, their songs were not, in any manner, mere imitations of a foregone style. The Romantic era "DNA" is clearly present, yet they were modern compositions at the vanguard of a new style of a uniquely American music, authentic reflections of their culture and time. Jazz musicians immediately recognized their enormous potential for use as the foundation of an improvisational art that required rich and robust harmonic and melodic resources that would provide countless artists a vehicle for authentic self- expression.

Jazz and classical music are thus inextricably and deeply linked—"twin sons from different mothers" indeed. Considering even just this one sonority—dominant seventh chords—reveals a consensus between the two disparate styles that is truly remarkable. I will end with a quote from a previous article on the similarities in the development of the two genres:

These are two of the most celebrated genres of "art music," for lack of a better term, but their origins could not be more disparate. The creative geniuses in each genre are separated by hundreds of years. They come from different continents, different cultures, different races, different political systems, and different folk music roots. As such, the two genres are, on the surface, very different from one another, and yet, the humanity and creativity that shines through across time and space speak to something else at play here—an unfathomably deep connection that defies the temporal, geographical, racial, and cultural differences, revealing instead the shared human spirit that is manifested in these powerful artistic expressions.

Special thanks to Dr. Bill Ryan for the kind assistance with the examples.

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