Harding has been conductor of the Trondheim Symphony Orchestra ( 1997-2000 ) , the Deutsche Kammerphilharmonie Bremen ( 1999-2003 ) and the Mahler Chamber Orchestra ( since 2003 ) . Harding has been music director of the Trondheim Symphony Orchestra ( 1997 â `` 2000 ) , the Deutsche Kammerphilharmonie Bremen ( 1999 â `` 2003 ) and the Mahler Chamber Orchestra ( since 2003 ) .