Given the question: What is the last name of the person who joined the kindergarten class at the Froebel Institute at the age of five?  Answer the above question based on the context below:  Descriptions of Imogen as a small child indicate that she had blue eyes, fair hair, an oval face reminiscent of her father's, and a rather prominent nose inherited from her mother.  In 1912, at the age of five, she joined the kindergarten class at the Froebel Institute, and remained at the school for five years. Summers were often spent at the Holsts' rented country cottage at Thaxted in Essex, where Gustav Holst began an annual Whitsun Festival in 1916.In 1917 Imogen began boarding at Eothen, a small, private school for girls in Caterham, where Jane Joseph, Gustav's star pupil from SPGS, taught music.  A letter home, dated 17 July 1917, tells of "compertishions [sic], and ripping prizes, and strawberries and cream for tea".  At the school, Imogen studied piano with Eleanor Shuttleworth, violin with André Mangeot (described as "topping") and theory with Jane Joseph ("ripping"). Under Joseph's tuition Imogen produced her first compositions—two instrumental pieces and four Christmas carol tunes—which she numbered as Ops. 1, 2, and 3. In the summer term of 1920, she composed and choreographed a "Dance of the Nymphs and Shepherds", which was performed at the school under her direction on 9 July.Imogen left Eothen in December 1920 hoping to study under Ruby Ginner at the Ginner-Mawer School of Dance and Drama, but was rejected on health grounds, although there appeared to be no significant medical issue. She then studied at home under a governess, while waiting to start at St Paul's Girls School in the autumn. At Whitsun 1921 she took part as a dancer in her father's production of Purcell's semi-opera from 1690, Masque of Dioclesian, held in the St Paul's School grounds and repeated a week later in Hyde Park.In September 1921 Imogen began at St Paul's Girls School, and became a boarder from Spring 1922. In July 1922 she performed a Bach Prelude and Fugue on the piano, for which Joseph praised her warmly, writing: "I think everyone enjoyed the Bach from beginning to end, they all made nice contented noises at the...
The answer is:
Holst