A player piano is a type of mechanical piano that plays music automatically using a system of perforated paper rolls. When the roll is fed into the piano, it activates the keys and hammers, allowing the instrument to perform pieces without human intervention. This invention became popular in the late 19th and early 20th centuries, providing entertainment in homes and public spaces. The player piano is often associated with the rise of mechanical music devices and the early days of recorded music. It allowed people to enjoy piano music even if they did not know how to play the instrument themselves, making music more accessible to the general public.