Although root position and second inversion Neapolitans exist, first inversion is normally used. When in this inversion, the Neapolitan is commonly called a Neapolitan sixth.




In this inversion, the Neapolitan is called a Neapolitan sixth.




Notice that the Neapolitan sixth's bass note is the same as a first inversion iio (or ii) or a root position iv (or IV).




For this reason, it often substitutes for these chords. Hence, it primarily functions as a predominant.




Consider this example.




We can replace the ii6 chord with a Neapolitan sixth. Listen to the new example.




Next, consider this example.




This time, we will replace the IV with a Neapolitan sixth.




Use this chart to reference the Neapolitan chord's usage. Listen to the new example.