Task: Question Generation
Input (English): Passage: Holst was given a spectacular send-off. The conductor Adrian Boult recalled, "Just before the Armistice, Gustav Holst burst into my office: 'Adrian, the YMCA are sending me to Salonica quite soon and Balfour Gardiner, bless his heart, has given me a parting present consisting of the Queen's Hall, full of the Queen's Hall Orchestra for the whole of a Sunday morning. So we're going to do The Planets, and you've got to conduct'." There was a burst of activity to get things ready in time. The girls at St Paul's helped to copy out the orchestral parts, and the women of Morley and the St Paul's girls learned the choral part in the last movement.The performance was given on 29 September to an invited audience including Sir Henry Wood and most of the professional musicians in London. Five months later, when Holst was in Greece, Boult introduced The Planets to the general public, at a concert in February 1919; Holst sent him a long letter full of suggestions, but failed to convince him that the suite should be played in full. The conductor believed that about half an hour of such radically new music was all the public could absorb at first hearing, and he gave only five of the seven movements on that occasion.Holst enjoyed his time in Salonica, from where he was able to visit Athens, which greatly impressed him. His musical duties were wide-ranging, and even obliged him on occasion to play the violin in the local orchestra: "it was great fun, but I fear I was not of much use". He returned to England in June 1919.
Output (English): What is the last name of the person to whom Holst sent a long letter full of suggestions about The Planets?