How many movies have Mirella Freni and Nicolai Ghiaurov acted in together?

They have worked on 6 movies together! Their first movie together was Verdi: Simon Boccanegra (1978) while their highest rated movie together was Verdi Ernani (1982). They have not worked together since A Christmas Celebration: Send Round the Song (1992). They are most known for their music films together.