Russian-born composer Igor Stravinsky had an almost incalculable effect on the development of 20th-century music. Known for his powerful and unusual rhythms, his first ballets, The Firebird (1910) and Petroushka (1911) caused a sensation in the artistic world. Throughout his life, Stravinsky was known for his progressive approach; he was always open to new techniques and applied them to his music. Among his most important works are Les Noces (1917), Pulcinella (1920), Orpheus (1948), Agon (1957) and perhaps the most famous, The Rite of Spring (1913).