I'm counting on my memory which has been kind of off lately ;)

Rosario Bourdon conducted the first concert in 1934.  Then Wilfrid
Pelletier became the musical director.  After Pelletier came Desire
Defauw in 1940, Igor Markevitch in 1957.  Zubin Mehta was at the helm
from 1961-67.  Franz-Paul Decker was a long time conductor (1967-1975),
Rafael Fruhbeck de Burgos (1975-1976), and Charles Dutoit, Music Director
since 1977.

p.s. I kind of cheated since this information is available on the MSO web
site:

   http://www.osm.ca/en/osm_musiciens/historique.asp

Bernard Savoie