David Robertson to Lead Sydney Symphony David Robertson, the music director of the St. Louis Symphony, has taken on a position on the other side of the world, becoming artistic director and chief conductor of the Sydney Symphony in Australia starting in 2014. Mr. Robertson will succeed Vladimir Ashkenazy as the orchestra's leader. His contract in Sydney runs through 2018. Mr. Robertson, who first appeared as a guest conductor in Sydney in 2003, assumed his post in St. Louis in 2005, when he also became principal guest conductor of the BBC Symphony Orchestra. The Sydney Symphony seems to have made an attractive offer. In its announcement of the appointment the orchestra said Mr. Robertson would take part in at least two CD recording projects a year, a yearly concert performance of an opera, regular commissioning of new works in collaboration with other orchestras and annual touring, with a focus on China. Much of the Sydney Symphony's season takes place during the off months at St. Louis. Mr. Robertson's contract in St. Louis ends with the 2013-2014 season, but a spokesman there said he and the orchestra were in discussions to extend his tenure.