After a certain point in the game, KK Slider occasionally visits the player’s island in Animal Crossing: New Horizons giving players have the opportunity to request any of his songs for a live concert.
Much like in previous games, KK Slider has a few secret “Error Songs” which he will play in the event players type in songs that he does not recognize.
In Animal Crossing: New Horizons, there are three potential songs he can play, the first being the theme of Animal Crossing: Wild World, and the other two being entirely new songs that have never been featured in the games before.
If you’re curious about these songs and don’t want to wait for KK Slider to visit your town, Gamexplain has helpfully published a short video featuring all three Error Songs which you can watch below: