The 1910s were a decade of change for the symphonic form, which had by then existed for well over a century. Meanwhile, various landmark works in other genres had presented further radical developments. In 1909, Arnold Schoenberg pushed for more and more dissonant and chromatic harmonies in his Five Pieces for Orchestra, Op. 16. From 1910–1913, Igor Stravinsky premiered his innovative and revolutionary ballets "The Firebird", "Petrushka", and "The Rite of Spring". Maurice Ravel and Claude Debussy were at work developing and performing their impressionistic music. Though he had been in the public spotlight for nearly twenty years, Sibelius found his works receiving poor reviews for the first time with the 1911 premiere of his Symphony No. 4 and, as James Hepokoski has written, "was beginning to sense his own eclipse as a contending modernist."