Aesthetics is a sub-discipline of philosophy. In the 20th century, important contributions to the aesthetics of music were made by Peter Kivy, Jerrold Levinson, Roger Scruton, and Stephen Davies. However, many musicians, music critics, and other non-philosophers have contributed to the aesthetics of music. In the 19th century, a significant debate arose between Eduard Hanslick, a music critic and musicologist, and composer Richard Wagner regarding whether instrumental music could communicate emotions to the listener. Wagner and his disciples argued that instrumental music could communicate emotions and images; composers who held this belief wrote instrumental tone poems, which attempted to tell a story or depict a landscape using instrumental music. Although history portrays Hanslick as Wagner’s opponent, in 1843 after the premiere of Tannhäuser in Dresden, Hanslick gave the opera rave reviews. He called Wagner, “The great new hope of a new school of German Romantic opera.” Thomas Grey, a musicologist specializing in Wagnerian opera at Stanford University argues, “On the Beautiful in Music was written in riposte of Wagner’s polemic grandstanding and overblown theorizing.” Hanslick and his partisans asserted that instrumental music is simply patterns of sound that do not communicate any emotions or images.