Task: Question Answering
Input (English): Passage: Boult was born in Chester, Cheshire, in North West England, the second child and only son of Cedric Randal Boult (1853–1950), and his wife Katharine Florence née Barman (d. 1927). Cedric Boult was a Justice of the Peace and a successful businessman connected with Liverpool shipping and the oil trade; Cedric and his family had "a Liberal Unitarian outlook on public affairs" with a history of philanthropy. When Boult was two years old the family moved to Blundellsands, where he was given a musical upbringing. From an early age he attended concerts in Liverpool, conducted mostly by Hans Richter. He was educated at Westminster School in London, where in his free time he attended concerts conducted by, among others, Sir Henry Wood, Claude Debussy, Arthur Nikisch, Fritz Steinbach, and Richard Strauss. His biographer, Michael Kennedy, writes, "Few schoolboys can have attended as many performances by great artists as Boult heard between 1901 and October 1908, when he went up to Christ Church, Oxford." While still a schoolboy, Boult met the composer Edward Elgar through Frank Schuster, a family friend.At Christ Church college at Oxford, where he was an undergraduate from 1908 to 1912, Boult studied history but later switched to music, in which his mentor was the musical academic and conductor Hugh Allen. Among the musical friends he made at Oxford was Ralph Vaughan Williams, who became a lifelong friend. In 1909 Boult presented a paper to an Oxford musical group, the Oriana Society, entitled Some Notes on Performance, in which he laid down three precepts for an ideal performance: observance of the composer's wishes, clarity through emphasis on balance and structure, and the effect of music made without apparent effort. These guiding principles lasted throughout his career. He was president of the University Musical Club for the year 1910, but his interests were not wholly confined to music: he was a keen rower, stroking his college boat at Henley, and all his life he remained a member of the Leander Club. 
Question: What is the last name of the person whose mentor was the musical academic and conductor Hugh Allen?
Output (English): Boult.