Task: Question Answering
Input (English): Passage: Peter Hall directed the Bayreuth Ring after Chéreau. His version, staged 1983–86, portrayed the natural innocence of the Rhinemaidens in the simplest of ways; they were naked. Keith Warner adapted this feature in his Ring production for the Royal Opera House Covent Garden, first staged 2004–06. A Covent Garden spokesman explained "The maidens are children of innocence, a vision of nature – and as soon as someone appears they hastily throw on some clothes to protect their modesty." While Warner relies on lighting to achieve an underwater effect, Hall used a Pepper's ghost illusion: mirrors at a 45° angle made the Rhinemaidens appear to swim vertically when the performers were in fact swimming horizontally in a shallow basin.Although the roles of the Rhinemaidens are relatively small, they have been sung by notable singers better known for performing major roles in Wagnerian and other repertoire. The first person to sing the part of Woglinde in full was Lilli Lehmann at Bayreuth in 1876. In 1951, when the Bayreuth Festival re-opened after the Second World War, the same part was taken by Elisabeth Schwarzkopf. Other Bayreuth Rhinemaidens include  Helga Dernesch who sang Wellgunde there between 1965 and 1967. Lotte Lehmann  played Wellgunde at the Hamburg State Opera between 1912 and 1914 and the Vienna State Opera in 1916.   Recorded Rhinemaidens have included Sena Jurinac for Furtwängler and RAI, Lucia Popp and Gwyneth Jones for Georg Solti, and Helen Donath and Edda Moser for Karajan. 
Question: What is the first name of the person who relies on lighting to achieve an underwater effect?
Output (English): Keith.