How many movies have Arturo Toscanini and Hal Keith collaborated on?

They have worked on 4 movies together! Their first movie together was Toscanini: The Television Concerts, Vol. 1: Wagner (1948) and was their highest rated movie together. They have not worked together since Toscanini: The Television Concerts, Vol. 4: Mozart, Dvorak, Wagner (1948). They are most known for their music films together.