Cosmé McMoon (born Cosmé McMunn; February 22, 1901 – August 22, 1980) was a Mexican-American pianist and composer, best known as the accompanist to notably tone-deaf soprano Florence Foster Jenkins, (born July 19, 1868 – November 26, 1944) was an American socialite and amateur soprano who was known and mocked for her flamboyant performance costumes and notably poor singing ability, Jenkins's full given name?