Burning Desires. Lynn Walker discusses favourite operatic moments with a series of guests. 1: Ralph Koltai. During his 50-year career Ralph Koltai 's designs have transformed the stages of opera houses around the world. Amonghis most precious memories are Visconti's stunning production of Verdi's Don Carlos from the fifties and Beecham's extraordinary recording of Puccini's La Boheme. Producer Michael Surcombe