According to Smith, Volpe is writing the book, tentatively titled "The Toughest Show on Earth: How I Ran the Metropolitan Opera for 16 Years and Survived," with New Yorker editor and writer Charles Michener. Giuliani declined to comment on these assertions.

Volpe, a onetime carpenter at the Met, is known as a demanding and powerful executive who has dealt unflinchingly with the world's most prominent singers. Perhaps his most talked-about episode came in 1994, when he fired the famously difficult soprano Kathleen Battle, citing her "unprofessional actions."