The Neapolitan Chord

Introduction: A Dark, Lowered Second

The Neapolitan chord is a major triad built on the lowered second scale degree (♭2̂). In A minor it's B♭–D–F; in C minor, D♭–F–A♭. It's named after the 18th-century Neapolitan opera composers who used it for moments of grief and pathos, though it was common all over Europe. Almost always it appears in first inversion, so we call it the Neapolitan sixth, written N⁶ (some books write ♭II⁶).

You'll hear it in Beethoven's "Moonlight" Sonata, in Chopin's C-minor Prelude, all over film scores at moments of dread, and as the crushing ♭II–i half-step of heavy metal riffs.

Click any example to hear it. The Neapolitan is shown in red.

Spelling the Neapolitan

1. Find 2̂ in the key and lower it a half step: that's the root.
2. Build a major triad on it. In a minor key, ♭2̂ is the only accidental (the 3rd is 4̂ and the 5th is ♭6̂, both already in the key).
3. In a major key, the Neapolitan is borrowed through mixture, so both ♭2̂ and ♭6̂ need accidentals (in C major: D♭–F–A♭).

Function and Voice Leading

The Neapolitan is a predominant: it substitutes for iv or ii°⁶, and like them it has 4̂ in the bass. (N⁶ is really iv with ♭2̂ in place of 5̂.)

• Double the bass (4̂), the third of the chord. Don't double ♭2̂.
• ♭2̂ moves down: to the leading tone (a diminished 3rd, ♭2̂–♯7̂) when N⁶ goes straight to V, or to 1̂ when it goes to a cadential six-four or to vii°⁷/V.
• Avoid moving ♭2̂ up to ♮2̂ in the same voice (an augmented unison). The clash between ♭2̂ in one chord and ♮2̂ in the next is accepted when ♭2̂ resolves down, but keep it out of the outer voices if you can.
• The bass usually rises from 4̂ to 5̂, or passes chromatically 4̂–♯4̂–5̂ under vii°⁷/V.

Three Ways to Resolve N⁶

Root Position and Tonicized ♭II

In Romantic music the Neapolitan also appears in root position (labeled N or ♭II), and composers sometimes tonicize it with its own dominant (V⁷/♭II) or even modulate to it for a moment. In pop and metal, ♭II often appears as a bare power chord sliding down a half step to i: the Phrygian sound (E–F–E in E minor), which isn't functioning as a predominant at all but as pure color.

Try It: The Neapolitan Resolver

Summary

• The Neapolitan is a major triad on ♭2̂, usually in first inversion (N⁶).
• It's a predominant; in minor its only accidental is ♭2̂, and in major it's borrowed through mixture.
• Double the bass (4̂); ♭2̂ moves down: to ♯7̂ before V, or to 1̂ via i⁶₄ or vii°⁷/V.
• Root-position ♭II and the Phrygian ♭II–i are Romantic and modern extensions.

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