Streep plays the title character, a real-life, New York society dame and patron of the arts who pines for a career of her own on the stage, in the 1940s-set dramedy. Problem is she is an abominable singer, but doesn't appear to realize it.
Grant plays St. Clair Bayfield, the devoted husband who valiantly attempts to protect Florence from critics who might reveal to her that she can't carry a tune. Because Florence contracted syphilis from her first husband decades earlier, Florence and Bayfield have never had sex, causing Bayfield to engage in extramarital affairs, despite his clear affection for his wife.
"Peering into other people's relationships, it's almost always not what you think it is from the outside," Streep said at a New York press conference promoting the movie Tuesday.
"And I think it's an accurate portrayal of realistic, delusional love, OK. It's realistic because it is what it is and there is illusion in it that they both prop up and keep aloft, this little bubble of happiness," she explained.
"In the margins, you feel the war. It just comes in every once in awhile with some glaring headline about something horrible happening -- there's so many analogies to now -- figuring out what makes life worth living. And love and art, as far as I'm concerned, is right smack in the middle. So, the compromises that people make to keep their happiness intact, I think that's all in the service of good."
"I think Bayfield had convinced himself that they did have an understanding, that things were fine. But clearly they're not really fine," Grant noted. "Somewhere, deep inside, they are troubling, but you have to cut him a little slack because poor, old Florence did have syphilis and that's tricky. It's a bit of a passion killer."
The film is set to open in U.S. theaters Friday.