Proto-Cubism that Metzinger was the first to recognize explicitly and implicitly the significance of the use of "a free, mobile perspective", and the "mixing... of the successive and the simultaneous". He was the first to write of the fact that artists had abandoned traditional perspective and were now free to move around their subjects to paint them from various points in space, and at various moments in time. Metzinger's role at center of Cubism both as a painter and theorist prompted Guillaume Apollinaire to write of Picasso, Braque and Metzinger as the first three Cubist painters. Now well beyond the teachings
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