Having started his career in the footsteps of Richard Wagner and Richard Strauss under the tutelage of Alexander von Zemlinsky, Schoenberg proved himself to be an absolute master in the late-Romantic tradition, best illustrated by his mighty cantata Gurre-Lieder. Yet he felt a strong need to create a language for music in the same way Wassily Kandinsky had done for painting. It led to his first atonal works, around 1908, and the invention of his 12-tone technique, around 1921, which he refined with his pupils Anton Webern and Alban Berg. It threw open the doors for successive generations of composers and changed the language of music forever.