FIGURE 17.1. The Neapolitan Sixth Chord
The N6 chord progresses to dominant harmony or dominant harmony decorated by tonic six-four. When resolving to the dominant chord the lowered supersonic (root of N6) moves to the leading tone (third of V). This produces a cross relation which is not objectionable.

FIGURE 17.2. Progressions of the Neapolitan Sixth
The Neapolitan chord may occur in root position progressing to a root position tonic chord. The fifth will ascend to the tonic to avoid parallel fifths.

FIGURE 17.3. Voice Leading of the Neapolitan Chord in Root Position
The Neapolitan sixth chord may be preceded by its secondary dominant or secondary dominant seventh chord.

FIGURE 17.4. The Neapolitan Sixth Preceded by Secondary Dominant
Chords similar to the Neapolitan chord maybe found on other scale degrees progressing to other than dominant chords.