In Wild World and City Folk
In Wild World and City Folk, the Music Box is a square box that plays the main theme of Animal Crossing when opened. It is obtained from Katie after returning her to her mother, Kaitlin, in another town. After escorting her back to her mom, she will mail the player a gift, containing one of nine exclusive items, one of which being a Music Box.
In New Leaf
In New Leaf, the Music Box is a decorative white clam shell that plays a music box version of a K.K. Slider song. It can be obtained from Cyrus after bringing him a Giant Clam Shell, a K.K. Slider song, and 3,000 Bells. After half an hour, he will return a Music Box to the player. The player can then put it in a Museum Shop exhibit or in their house.
Players can hit the A button and hear the song. It does not repeat, so to hear the song again, they should hit the A button again. In addition, much like with stereos, only one Music Box may play in a room at any one time. If the player activates a Music Box and then tries to activate another, the previous Music Box will deactivate itself. However, a Music Box and stereo can be activated in the same room with no issues.
A Music Box can be seen in Anabelle, Cally, Diana, and Nana's default houses. In Animal Crossing: New Leaf - Welcome amiibo, Pascal's RV has a "Pondering" Music Box available for purchase, which costs 3 MEOW Coupons.
In New Horizons
The Music Box feature was added to Animal Crossing: New Horizons with the version 2.0 update. Unlike its appearance in New Leaf, there are only two music boxes that can play any songs by inserting the song onto the track list instead of being individual furniture items for each songs.
The following is a list of all music box songs in New Leaf and New Horizons.
The Music Box in Animal Crossing: Wild World