The Town Tune is the small melody that plays whenever the player talks to a character, when you walk into a door, and also the small melody that plays whenever the Clock Tower bell rings on the hour. A town tune can range anywhere from 1 to 15 notes, as well as the ability to choose one that will play a random note. In the original Animal Crossing, you could change your town tune by facing the billboard next to the Post Office. In Animal Crossing: Wild World and Animal Crossing: City Folk, you can change the town tune by going to the civic center in the Town Hall. Talk to Pelly or Phyllis, select Town Tunes, and adjust the notes to your liking.
Town tunes can also be played on instruments that can be bought in Tom Nook's. If music is playing at the same time, the instrument plays at the same speed.
Sometimes, when town tunes are played while talking to a character, it can relate to the villager's species.
Cranky villagers may make the tune sound somewhat strange, peppy villagers will make the tune sound bouncy and normal villagers will take your tune and make it perky. In Animal Crossing, sometimes villagers will tell you to change the town tune, and the snooty ones might refer the Town Tune as "the board with the little froggies on it."