Prepared piano is a technique where objects are placed on or between the strings of a piano to alter its sound. This can include items like screws, rubber, or felt, which create unique timbres and textures when the piano is played. The concept was popularized by composer John Cage in the mid-20th century, expanding the traditional role of the piano in music. The prepared piano allows for a wide range of sonic possibilities, transforming the instrument into a percussive sound source. This innovative approach has influenced various genres, including contemporary classical and experimental music, encouraging composers to explore new auditory experiences.