Various styles of music are popular in the UK, including the indigenous folk music of England, Wales, Scotland and Northern Ireland. Notable composers of classical music from the United Kingdom and the countries that preceded it include William Byrd, Henry Purcell, Sir Edward Elgar, Gustav Holst, Sir Arthur Sullivan (most famous for working with the librettist Sir W. S. Gilbert), Ralph Vaughan Williams and Benjamin Britten, pioneer of modern British opera. Sir Harrison Birtwistle is one of the foremost living composers. The UK is also home to world-renowned symphonic orchestras and choruses such as the BBC Symphony Orchestra and the London Symphony Chorus. Notable conductors include Sir Simon Rattle, Sir John Barbirolli and Sir Malcolm Sargent. Some of the notable film score composers include John Barry, Clint Mansell, Mike Oldfield, John Powell, Craig Armstrong, David Arnold, John Murphy, Monty Norman and Harry Gregson-Williams. George Frideric Handel became a naturalised British citizen and wrote the British coronation anthem, while some of his best works, such as ''Messiah'', were written in the English language. Andrew Lloyd Webber is a prolific composer of musical theatre. His works have dominated London's West End since the late 20th century and have also been a commercial success worldwide.