A chromatic chord. It is a major common chord on the flattened supertonic in its 1st inversion, e.g. in key C it comprises F–A♭–D♭. Reason for its name is unknown, since it occurs in 17th‐cent. mus. before the so‐called Neapolitan sch. existed, e.g. in mus. by Carissimi, Corelli, and Purcell (in King Arthur).