I saw Dunaway's Callas in Boston, and thought she was simply dreadful. All one note. Those mannerisms intact. Norma Desmond would exploit that side of Dunaway; but the show is built on the songs taking the roof off, though people who saw Moreno in London said it was her acting that sold it.
Did anyone else see a Norma who wasn't a stellar vocalist? Even Petula Clark had the notes (if an odd American accent.)