If your knowledge of traditional Italian music begins and ends with “O Sole Mio,” Neapolitan Heart isn’t going to hold your hand. Or maybe it is: Director Paolo Santoni is more concerned with the sentiment of the classic music than its history, and as the documentarian trolls neighborhoods from New York to Naples investigating the current state of musica napoletana, most of the insight regarding the songs runs along the lines of “Listening to them always does you good.” The performers, most of them old men and one of them Jerry Vale, are interviewed at length but often not identified until the end credits—a decision that might leave the uninitiated viewer questioning the significance of what’s being presented. The emotion of Neapolitan Heart, however, is indisputable: A Buena Vista Social Club for Italians, the movie is full of passion, keeping the company of lively folks who can warble mournfully of broken hearts but would much rather croon lustfully about a lover’s rosebud mouth. Santoni highlights the romance and melodrama of the sound reportedly gleaned from “Arab laments and Spanish folk songs” by weaving in scenes of outsized swooning and longing stares from the silent movies that became popular during the music’s golden age. Because many modern singers of Neapolitan music perform at weddings and other celebrations, the mood of this documentary is predominantly joyous, weighed down only by an oddly dark conclusion: a guttural interpretation of Peppe Barra’s war song “Tammurriata Nera,” a performance prefaced with words about the children of rape and accompanied by images of destruction. Press notes inform that the scene is meant “to emphasize the turning point in the evolution of Neapolitan music,” but nothing else in the movie indicates when or how the music turned. Still, Neapolitan Heart doesn’t completely lack for an explanation of the music it lauds: When describing its appeal, one performer clarifies that the songs are all about the beauty of love—and “never the banality of the relationship itself.” —Tricia Olszewski