Question: Roy Galbriath Henderson taught what English contralto singer that died of cancer during the height of her career? 
Sentence (from "Kathleen Ferrier"): Kathleen Mary Ferrier, CBE (22 April 19128 October 1953) was an English contralto singer who achieved an international reputation as a stage, concert and recording artist, with a repertoire extending from folksong and popular ballads to the classical works of Bach, Brahms, Mahler and Elgar.
Relevant evidence: Yes