Temperamental, volatile Spanish-born pianist and conductor whose life and career were varied and often controversial. Born in Valencia, he was a child prodigy, giving piano recitals by the age of seven and supplementing the family income by playing for up to 14 hours daily at a silent cinema theatre. He was an honours graduate from the Conservatoire de Musique in Paris, and, by the age of 24, occupied Franz Liszt's former post as leader of the piano department of the Geneva Conservatory. In 1928, he made his London debut as a concert pianist a…