For Live Music on the waterfront in Key Largo, the locals will tell you the Pilot House. It is excellent and is off the main road, so mostly only known by locals or people on their second vacation to the area. We recommend the happy hours, because you can really save some cash. Pull up by boat, as this is also the City Center Marina. Boat parking is plentiful. Great bar.
It is not hard to find the restaurant, just get over to Ocean Bay Drive. That is the road which runs next to DJ's Diner. That is a nice place too for the food, not Live Music or the waterfront. We stayed at the Bayside Inn at mile marker 99 and were so impressed with all the many restaurants. They are everywhere.
Has some really good salads. Got the Chicken Fiesta Salad off the specials menu. The recipe uses grilled chicken strips, cheddar cheese, fresh lettuce, guacamole, onions, black beans, and salsa fresca, and creamy chipotle dressing. Excellent!