San Francisco Ballet continued to serve as the school's director until his retirement in 1975. In 1938, the company's first major production was "Coppélia", choreographed by Willam Christensen. In 1940, it staged "Swan Lake", the first time that the ballet was produced in its entirety by an American company. On Christmas Eve 1944, the company staged "Nutcracker"—the first complete production of Tchaikovsky's most popular piece ever danced in the United States. In 1942, San Francisco Opera Ballet split into two independent companies, ballet and opera. The ballet half was sold to Willam and Harold Christensen. Willam became artistic director, while Harold took on
San Francisco Ballet de Coteau's battle with terminal cancer forced him to step down from the position. Emil de Cou, who had been serving as conductor since 1995, then assumed the role of music director, leading the Orchestra until 2001, when he left to join Washington D.C.'s National Symphony Orchestra. He was replaced by first associate conductor Jean-Louis LeRoux, who then left the interim position in 2003 and was succeeded by Andrew Mogrelia. In 2005, Mogrelia left in order to focus on his duties as music director at San Francisco Conservatory of Music. That same year, Martin West, frequent guest conductor for the