Although Castel performed throughout Europe, North America and South America, he was best known for his nearly 800 performances at The Metropolitan Opera, where he also served as staff diction coach for three decades.
Despite performing extensively throughout the world, including Europe, North America, and South America, Castel is best known for his extensive work with The Metropolitan Opera, where he performed over 800 times and also served as a diction coach for the company for thirty years.