My mom recommended Preservation Hall as a must do on my first trip to NOLA. I did a little bit of research to know that there is no food service, no drink service, no A/C, and no reservations. This place is bare bones, stripped down authentic jazz music by seasoned performers and we loved it! Some of the negative reviews discuss the lack of food and drink, the wait, and the lack of seating and A/C. This place is neither a restaurant nor a bar and also isn't in the business of packing people in like a Taylor Swift concert. Eat beforehand, grab drinks from Pat O'Brien's next door (you can bring them into PH), wear comfy/breathable clothing, and get to know your neighbor while waiting in line. It's a great and once of a kind musical experience.