Neapolitan 6th chord, which is equivalent to ♭II⁶. It's a major chord built on the flattened second degree of the scale (in C major ♭II⁶ would be D♭ major with F in the bass) It's usually always found in first inversion (hence N⁶) because the bass note (scale degree 4) smoothly leads up to the root of the V chord (scale degree 5) In other words it has predominant function and can be used as a spicy little substitute for a boring old iv chord
@@negativize_11 very fancy. the N6 is the major chord a half-step above your tonic (its the Db in first inversion for C major). jazz musicians often describe this as a tritone substitution, given Db (well, Db7) shares some some harmonic properties with the G7 chord.
