Conductor and composer, born in Lawrence, Massachusetts, USA. He played piano from childhood, and studied at Harvard and the Curtis Institute of Music, Philadelphia. As a Tanglewood conducting student (1940–1), he became a protégé of Koussevitsky. He was named assistant conductor of the New York Philharmonic and in 1943 made a sensation stepping in at the last minute for the indisposed Bruno Walter. There followed an active career as a guest conductor, and occasional pianist, during the 1940s. In that decade he also composed works including the Jeremiah and Age of Anxiety symphonies and the Broadway musical Fancy Free. In 1952 he premiered his one-act opera Trouble in Tahiti, and 1957 saw the debut of his classical musical West Side Story. The next year he began an 11-year tenure as conductor of the New York Philharmonic and a series of televised Young Peoples’ Concerts which, combined with his engaging personality and extravagant conducting style, made him the most popular conductor in the country. In later years he guest-conducted worldwide, having spent his early career championing conservative American composers such as Copland, and in the 1970s spearheaded the Mahler revival.