More than two years after his highly public divorce from the Montreal Symphony Orchestra, Charles Dutoit remains at the top of guest conducting wish lists in Pittsburgh, Dallas, Minneapolis, and countless other cities. The change in his primary role, from being at the helm of one or two orchestras to that of a hired gun, has allowed Dutoit to refocus his energies on maintaining what he calls the “Russian-French” tradition of conducting. That tradition is one of the modern music world’s last connections to the old days of Koussevitsky and Monteux, and Dutoit clearly sees himself as one of the last guardians of the classic orchestral form.