What [Tullio Serafin] said that impressed me was: "When one wants to find a gesture, when you want to find how to act on stage, all you have to do is listen to the music. The composer has already seen to that." If you take the trouble to really listen with your soul and with your ears — and I say soul and ears because the mind must work, but not too much also — you will find every gesture there. And it is all true, you know.

On advice from Tullio Serafin, in "Harewood Conversations - 1968", an interview in Paris with Lord Harewood for the BBC (April 1968) on Maria Callas : The Callas Conversations (2004) EMI Classics DVD