As young people flocked to their favorite clubs on Saturday night, Terrace Tavern, seated right on Long Beach Boulevard in Beach Haven Terrace, appeared deceptively calm from the outside. Passersby would never imagine the quiet facade of a classic family-owned business masked a vibrant musical storm unfolding within its walls.

With the simple opening of a door, the sounds of music and friendly chatter spilled into the street, transporting visitors from the outside world into a still-quaint…