Kent Nagano won’t officially become music director of l’Orchestre symphonique de Montréal until fall 2006, but the unusually soft-spoken maestro is already making his presence felt. Compared with the imperious Charles Dutoit, whose 23-year tenure at the Montreal helm ended in bitter fashion two years ago, Nagano is a decidedly new kind of director for the OSM, promoting a studious and humble approach to music-making, even as he speaks of the importance of building trust with audiences and begins to reshape the sound of the orchestra itself.