What is fantasia in c minor bach?

Fantasia in C minor is one of the most famous pieces written by Johann Sebastian Bach. It is a keyboard composition that dates back to the mid-18th century, and has since become one of his most popular works. The piece is composed in three movements and was likely written as an improvisation, with the composer intending it to be performed by himself at a keyboard instrument. The Fantasia in C minor is characterized by its dark and emotional texture, with a sense of restlessness and conflict throughout. It is often regarded as an early example of Bach's virtuosic keyboard techniques, and is considered an important work in the history of Western music.