Jean Metzinger see the cubist works in Room 7 and 8. While Pablo Picasso and Georges Braque are generally acknowledged as the founders of the twentieth-century movement that became known as Cubism, it was Jean Metzinger, together with Albert Gleizes, that created the first major treatise on the new art-form, "Du "Cubisme"", in preparation for the Salon de la Section d'Or held in October 1912. "Du "Cubisme"", published the same year by Eugène Figuière in Paris, represented the first theoretical interpretation, elucidation and justification of Cubism, and was endorsed by both Picasso and Braque. "Du "Cubisme"", which preceded Apollinaire's well known essays,
20th-century classical music explored in their respective articles. At the end of the 19th century (often called the "Fin de siècle"), the Romantic style was starting to break apart, moving along various parallel courses, such as Impressionism and Post-romanticism. In the 20th century, the different styles that emerged from the music of the previous century influenced composers to follow new trends, sometimes as a reaction to that music, sometimes as an extension of it, and both trends co-existed well into the 20th century. The former trends, such as Expressionism are discussed later. In the early part of the 20th century, many composers wrote