In 1900 he entered the Royal Academy of Music where he studied the piano. Influenced by the Celtic Revival and Irish poetry, he wrote in 1909 the symphonic poem In the Faëry Hills. He spent the year 1910 in Russia. During the following years, under the pseudonym Dermot O'Byrne he published short stories and poems in Ireland, where he spent much time. In 1916 and 1917 he wrote three symphonic poems, The Garden of Fand, Tintagel, and November Woods, which established his reputation. His ballet, The Truth About the Russian Dancers, on a scenario by the playwright J.M. Barrie, was produced by Sergey Diaghilev in 1920. Between 1921 and 1939 he wrote seven symphonies dedicated to the musicians he admired, among them John Ireland and Jean Sibelius. He also wrote numerous piano and chamber works, including a sonata for viola and harp (1928) and a nonet for winds, strings, and harp (1931). Living for long periods on the coasts of Ireland and Scotland, he wrote music that was romantically evocative and richly orchestrated. He was knighted in 1937 and in 1941 was appointed Master of the King's Musick.