How many movies have Christa Ludwig and Herbert von Karajan acted in together?

They have worked on 4 movies together! Their first movie together was Madama Butterfly (1974) while their highest rated movie together was Beethoven · Missa Solemnis - Herbert von Karajan (2020). They have not worked together since Beethoven · Missa Solemnis - Herbert von Karajan (2020). They are most known for their music films together.