How many movies have Ennio Morricone and Vanni Castellani collaborated on?

They have worked on 4 movies together! Their first movie together was That Splendid November (1969) while their highest rated movie together was Salò, or the 120 Days of Sodom (1976). They have not worked together since Salò, or the 120 Days of Sodom (1976). They are most known for their drama films together.