"Neapolitan" is a K.K. Slider song. It sounds similar to the music in the city. "Neapolitan" means "from Naples," Naples being the largest city in southern Italy. True to its title, the song incorporates Italian motifs. It seems to have a Wurlitzer and a piccolo at one point. Curlos, Drake, and Teddy are on the album cover, wearing Italian outfits. Neapolitan did not appear in the original Animal Crossing.
Elise, Erik, Anicotti (in Animal Crossing: New Leaf) and Ketchup have this song playing in their houses.