Who said "I learned that true freedom comes from discipline."?

This quote is attributed to Maria Callas.

I learned that true freedom comes from discipline. - Maria Callas

"I learned that true freedom comes from discipline."

Maria Callas Freedom

Opera Soprano Greek-American 1923–1977

"You have to fight to reach your dream. You have to sacrifice and work hard for it."

"If music is the food of love, play on."

"I am my own sanctuary and I can be reborn as many times as I choose throughout my life."

"The mission of an artist is to save the soul of mankind."

"Freedom to pursue your passion is precious."

"Freedom comes at a cost."

"Order isn't restriction. It's freedom."

"Freedom comes with responsibility"