Town Hall Tune
From Nookipedia, the Animal Crossing wiki
The Town Hall Tune actually has three tunes- there is a day tune and a night tune as well a New Leaf tune. The day tune is when Pelly is at the front desk. The night tune is when Phyllis, her sister, takes over for night shift. The New Leaf tune is played while Isabelle is on duty. They are both quite country themed, one brighter and the other darker.