Roy Galbriath Henderson taught what English contralto singer that died of cancer during the height of her career? 
Roy Henderson (baritone):  He later became a teacher of singing, his most notable student being Kathleen Ferrier. Kathleen Ferrier:  Her death from cancer, at the height of her fame, was a shock to the musical world and particularly to the general public, which was kept in ignorance of the nature of her illness until after her death.
i don't know