The Detroit Symphony may still be looking for a music director to replace the departed Neeme Järvi, but the ensemble is enjoying rising attendance and a stability that most other American orchestras would kill for. How did they accomplish such a thing in a city famed for its crippling poverty? Rather than simply making an appeal to the business community for help, the DSO has become a major investor in the urban revitalization of its hometown, and is endeavoring to show the community the same long-term commitment it requests from others.