Meryl Streep stars in the biopic “Florence Foster Jenkins” about a 1940s socialite who famously followed her musical dreams all the way to Carnegie Hall. We talk with the three-time Oscar winner about this movie role, plus her past roles and what it was like speaking at the Democratic National Convention.

FOX411: What the experience was like for you [speaking at the DNC]?
Meryl Streep: Oh you, know I was a cheerleader in high school, and I got out there and it felt like, ‘man this is the big game,’ you know, ‘we’re in the big league and our team… is gonna win,’ and it made me feel [for] all the women for 240 years -- that America has been a country and the first 150 we couldn’t even vote -- and here we are at this moment. I did feel the sort of throb of history and couldn’t contain myself. I didn’t, I wasn’t really aware that I screamed until I looked up at my kids in the box and they were both like this (covers face).

FOX411: At this point of your career obviously you can pick [which roles you take]. Is there a goal you have with the roles that you choose? A common theme?
Streep: There isn’t a theme because I’ve never -- I’m not a producer -- and I don’t have a company that looks for certain material. I’m completely dependent on what comes to me, but what comes to me is reflective of the world as it is in this moment. It’s what people will put money into, and I think I’m the beneficiary a certain, the same tide that brought Hillary [in] as a candidate -- the fact that I even am on screen at 67, or whatever I am, is kind of, it would have been unheard of even 10 to 15 years ago so that’s all good news.

FOX411: What is something you have done that was maybe outside of your comfort zone?
Streep: I made a movie called “The River Wild” years ago, and I am not an adrenaline junky. I am not someone who seeks thrills and this was so unbelievably scary. I can’t believe they insured the movie or me, I almost died a number of times, but I really got it. By the end of the thing, I really got those people that push themselves to the extreme.

FOX411: For “Florence Foster Jenkins” you have to sing off key. How did that effect the rehearsal?
Streep: Yes, I mean she went off the rails in a very specific way and we had the recordings of her doing that and so what I wanted to do was not copy her but capture the tambour of her voice, you know, which was particularly grating and also endearing. There was a sweetness to it. And we were lucky because Simon Helberg, who plays the accompanist Cosme McMoon, he and I share a comic sensibility and so we approached it very seriously, and then I tried to crack him up.

FOX411: What do you feel is more important -- level of talent or level of passion?
Streep: I think in life, for everybody, level of passion. Following what you love, following what you love. Because I think worst thing in the whole world is to wake up at 40 and realize that you’re not, you never ever tried that thing that you really wanted to try. She [Jenkins] carried to it to an absurd length but she was happy.

“Florence Foster Jenkins” hits theaters Aug. 12.

Fox News Entertainment Producer Ashley Dvorkin covers celebrity news, red carpets, TV, music, and movies. Dvorkin, winner of the 2011 CMA Media Achievement Award, is also host of "Fox 411 Country," "Star Traveler," "Fox 411 Big Screen," and "Fox on Reddit."