Neapolitan 6th

[Forte]

I'm a little unclear on neapolitan 6th chords. I know it has something to do with the ii chord, but that's about it.

Can someone elaborate on how it's constructed? Maybe a little about why it's useful and what music I can check out that makes use of it?

Thanks

[stevel]

Originally Posted by Forte

I'm a little unclear on neapolitan 6th chords. I know it has something to do with the ii chord, but that's about it.

Can someone elaborate on how it's constructed? Maybe a little about why it's useful and what music I can check out that makes use of it?

Thanks

"6th" chords mean what we'd call a "first inversion chord".

A Neapolitan Sixth Chord is a:

Major Triad built on lowered scale degree 2 (b2) in first inversion (so its bass note is scale degree 4).

In the key of C, the Neapolitan Sixth Chord is F Ab Db. If we dissect that, it's a Major triad on b2 - b2 in C is Db, so, Db F Ab, and put it in first inversion - F Ab Db.

In analysis, it is now typically labelled "N6" (with the 6 being superscript) or in older texts, bII6 (ditto).

N6 has some "typical" appearances:
1. It is usually in first inversion.
2. It most often occurs in minor keys.
3. It moves to a V chord.
4. The goal of the b2 note is the leading tone (so in C, the Db would move to B ).
5. Often, the b2 travels through scale degree 1 before going to the L.T., either as a non-chord tone, or as part of a I6/4 chord.

The Neapolitan Chord has some "unusual" appearances:
1. It may appear in root position or second inversion (2nd Inv. rare).
2. It may appear as a minor triad (extremely rare) or as a 7th chord (also rare).
3. It may have a secondary (applied) dominant used with it - Ab to N in C sounds like V/N to N.
4. It may also be a pivot chord in a modulation.
5. It may also be a key area to which a piece modulates.
6. It may act as a neighbor chord to I, or in some other non-pre-dominant capacity.

Of the typical appearances, remember, it is a pre-dominant chord - it goes to V. So don't get it confused with the jazz use of a tritone sub - a Db7 to C6 in Jazz uses the Db chord as a tritone sub for G7 making it a dominant function chord, rather than a pre-dominant function as in classical music.

By the way, you said it's "some type of ii" above, but actually, it's really a type of iv chord - F Ab C in cm - F Ab Db in cm - see the similarity - some chords evolved from "sixth chords" (which is why we call it a SIXTH chord) whose "root" is the bass note - so why we see them today as an inversion of some other chord, older composers (roughly before the early 1700s) saw them as unrelated - to them, the "root" of F Ab Db was F - it was "a chord of the sixth on F" to them.

The chord is especially popular with Italian (from Naples, hence the name) composers - I find it quite frequently in the guitar works of Giuliani, Carcassi, Sor, etc. I know there are certainly some in Mozart, Haydn, and Beethoven works, but they are sprinkled in. I'm sorry I don't know of any really obvious ones off hand. I do know that in Bach's 371 chorales, IIRC there's only 1 instance of a Neapolitan 6th chord. The minor Neapolitan (the only one I've ever seen) is in Schubert's Death and the Maiden quartet.

Best,
Steve

[stevel]

Originally Posted by Forte

music I can check out that makes use of it?

Oh, I just realized - Chopin's Prelude in C minor - the famous one - Op 28 no. 20. The final cadence is VI - N - V7 - i (so this is a root position - i.e. "less common" version).

Steve

[stevel]

Originally Posted by chckn8r

It's essentially a major 2nd chord - played in the 1st inversion.

It was one of those chords introduced in the baroque or early classical (music history class was such a long time ago... ) that added some "spice" to a progression - it's usually used as a substitute for a ii or a IV chord as a sub dominant chord usually preceding a V-I progression.

In Popular theory (or jazz), it's seen as a chord borrowed from the parallel Lydian scale - if playing C major (or Ionian), make the F# and you have a C Lydian scale - that's where the chord is from.

It works because it suggests a secondary dominant progression (in C, the secondary dominant to G7 would be D7), but as it is (in C, it's a D major chord with F# in the bass) it's weakened in that it's in the first inversion and does not have the 7th. In the era that it was "invented" it was not seen as that, it was a colourful chord with pizzaz and not a secondary dominant.

D

Not to be nit-picky D, but it is built on b2 not 2. Your example of the Lydian origin is incorrect. It's seen as being from the parallel PHRYGIAN mode - Phrygian has the necessary b2 to make the chord.

So D F# A in C is typically V/V, but can be just "II" in some circles (and that does come from Lydian in that case), but the Neapolitan is always Db F Ab (at least) in C.

Best,
Steve

[Ron Ofir]

According to my book, there's a Neaopolitan chord in Beethoven's "Moonlight Sonata" and Bach's "Small Prelude" (is there only one small prelude?).

[reith]

The Neapolitan 6th is so useful for smooth modulation into some remote keys as well as swapping from tonic major to minor and vice versa which can add interest to otherwise bland harmony.

To modulate from say, C major to A flat major use the N6:

C...Db...C....Bb...Ab
G...Ab...Ab..G.....Eb
E...F.....Eb...Db...C
C...F.....Ab...Eb...Ab

It's allowable to double the 3.rd in the N6
You can also use the root flat-IIa for modulation, taking care to avoid 5ths and 8ves.

[MaestroX]

The general consensus here states that N⁶ resolves onto V, though it is possible to resolve onto Ic, which would then obviously resolve to V. This allows a smooth stepwise movement in all voices.

I always think that to be able to really understand the function of such chords, one should play through them and see and hear them in real world settings.

Beethoven—Sonata, op. 27, no. 2
Beethoven—Sonata, op. 27, no.gif

Bach-Suite for Flute and Strings


Beethoven—Sonata, op. 90


Mozart—String Quartet, K. no. 42



Also, the N⁶ progression will usually create a false-relation. You can avoid this false relation by omitting the 5^th in V.

Hope this helps

[chckn8r]

Originally Posted by stevel

Not to be nit-picky D, but it is built on b2 not 2. Your example of the Lydian origin is incorrect. It's seen as being from the parallel PHRYGIAN mode - Phrygian has the necessary b2 to make the chord.

So D F# A in C is typically V/V, but can be just "II" in some circles (and that does come from Lydian in that case), but the Neapolitan is always Db F Ab (at least) in C.

Best,
Steve

Steve! Have you been on vacation?

Yes, you're absolutely right - that's what I get for not checking my theory texts after almost ... well, I won't get into how long it's been.

D

[stevel]

Originally Posted by Ron Ofir

According to my book, there's a Neaopolitan chord in Beethoven's "Moonlight Sonata" and Bach's "Small Prelude" (is there only one small prelude?).

That's right - thanks Ron - there is a pretty noticeable one in Moonlight.

Usually the English translation is "Little Prelude". I think there's a relatively well-known Little Prelude in C and that's probably what is meant, though I imagine there are other Bach "little" preludes. It's kind of like when someone says "Bach's 'Minuet in G' " we know they mean the one from the Anna Magdelena Notebook that begins D G A B C D G G | E C D E F# G G G

Of course, Bach probably wrote other Minuets in G, and in fact, he didn't even write that one! But we know which one people mean.

Steve

[stevel]

Originally Posted by chckn8r

Steve! Have you been on vacation?

Yes, you're absolutely right - that's what I get for not checking my theory texts after almost ... well, I won't get into how long it's been.

D

Yes - I actually was on Vacation! I'm back now and Chris showed me how to do superscript - so watch out, I'm going to be N⁶ ing you guys if you don't be careful!!!

I do a lot of theory, so it stays fresh. But I'd say, it's always a good idea to pick up something and go through it every once in a while just to keep it current - every time I re-read something I go "oh, so now I finally get what the author meant" - after having had it explained in other ways by other authors!

Best,
Steve