When encountering these chords in music theory classes, students often ask where the names came from—Crotch says: These [German, French, and Italian Augmented 6th Chords] and the Neapolitan sixes [sic ...

Perhaps the most famous use of the Neapolitan chord is in Ludwig van Beethoven’s “Moonlight Sonata,” (Piano Sonata No 14 in C# Minor, Op. 27, No. 2) from 1802.