Z - OST music by Mikis Theodorakis, a film by Costa-Gavras (1969

Z is a 1969 French language political thriller directed by Costa Gavras, with a screenplay by Gavras and Jorge Semprún, based on the 1966 novel of the same name by Vassilis Vassilikos. The film presents a thinly fictionalized account of the events surrounding the assassination of democratic Greek politician Gregoris Lambrakis in 1963. With its satirical view of Greek politics, its dark sense of humor, and its chilling ending, the film captures the sense of outrage about the military dictatorship that ruled Greece at the time of its making.[1]
Z stars Jean-Louis Trintignant as the investigating magistrate (an analogue of Christos Sartzetakis, who would many years later become President of Greece). International stars Yves Montand and Irene Papas also appear, but despite their star billing have very little screen time compared to the other principals. Jacques Perrin, who co-produced, plays a key role.
http://en.wikipedia.org/wiki/Z_(film)