5 stars. I found the concert venue by accident while walking around the archeological museum and it was one of the best things I've done after 4 days in Naples. If you love music, classical, opera, and want to learn about traditional Neopolitan culture - I would 100% recommend catching a concert at Napulitanata.
The venue is small and perfect for the acoustics of a singer, bowed double bass, piano, and flute. It is amazing to hear the bel canto resonance of an opera singer in a small hall - the human voice filling a hall, from just a few feet away.
This is a one of a kind musical experience. I got chills from the singer and pianist, and the vino rosso definitely didn't hurt xp. The musicians were awesome and you could tell the staff really loves music and Napoli. If you want a live music experience in Naples, definitely book a ticket early to get a seat.