Self-playing pianos are musical instruments that can play music automatically without human intervention. They use a system of mechanical or digital technology to read music and produce sound. These pianos can be programmed to play a variety of songs, making them popular for entertainment in homes, restaurants, and events. One common type of self-playing piano is the player piano, which uses a roll of paper with holes to trigger the keys. More modern versions, like digital pianos, can connect to computers or apps, allowing users to select and play music easily.