If you listen carefully to the guy who's playing an arch-top guitar and singing in that scene, you'll recognize his voice: it belongs to the guy who starred in the Neapolitan soap opera, "Senza Mamma," that Vito and Genco attended.
Ntra la porta tua lu sangu � sparsu, E nun me mporta si ce muoru accisu... E s'iddu muoru e vaju mparadisu Si nun ce truovo a ttia, mancu ce trasu.