Leonard Bernstein was an American composer, conductor, author, music lecturer, and pianist. He is one of the most significant figures in 20th century music and is best known for his compositions for West Side Story and Candide. Bernstein was also a prominent figure in the world of classical music, conducting many of the world's leading orchestras. He was a lifelong advocate for music education and was the first American-born conductor to lead the New York Philharmonic.