K.K. Lullaby is a song by K.K. Slider. When played on a stereo, the tune is played like a music box, with little metallic noises designed to relax the player. Unfortunately, they may be startled at the end of the song - the entire track rewinds to start again, sending out a quick succession of jumbled notes.
These villagers play K.K. Lullaby inside of their homes once they own a stereo.