Classical music is a broad term that designates the art music of Western cultures. The works performed by classical musicians are selected from a tradition of written music dating back to the Middle Ages. Much of this music was originally composed as church music or for the entertainment of the aristocracy. Starting about the mid 18th century, classical music began to be composed for a public of classical music listeners, and it is this audience that continues to support the tradition today. Classical music is commonly divided into historical eras, including Medieval, Renaissance, Baroque, Classical, Romantic, and Modern. Culturally, classical music stands out for the intensive training that serious participants must undergo, as well as the tendency of its listeners to cherish, even venerate, particular works and their composers.