09/15/2007 at 08:00 AM EDT
"Queen of Soul" Aretha Franklin will be joining Usher, Stevie Wonder, Ludacris, Garth Brooks, Robin Thicke and other all-stars for Sept. 18's Dream Concert
at Manhattan's Radio City Music Hall.
On her bus en route to New York, PEOPLE caught up with the slimmed-down singing legend, 65, to discuss her new look and what'son the road ahead.
It's no secret you've had some struggles with your weight in recent years.
Who hasn't had a weight issue? If not the body, certainly the big head! (Laughs.) But I have no such issues now.
How much have you lost?
A lot of weight. I won't say the number, but I found the magic numbers on the treadmill. Slowly but surely. It's all happy.
I would never, ever do that. I know many women who [had gastric bypass surgery]] who are having a bad time now, unfortunately. It's nothing I would ever do.
So, tell us about the Dream Concert
It's going to be one magnificent evening. We're trying to raise money [to build] the Martin Luther King Jr. Memorial on the National Mall [in Washington, D.C.]. It will stand between the Lincoln Memorial and the Jefferson Memorial, and I wanted to help because MLK Jr. was a family friend – and because I believe in what he was doing.
Have you been working on new music, too?
I have a single coming out in two weeks – a duet with Fantasia [Barrino], called "Let Me Put You Up On Game."
And a movie?
For television. My autobiography, From These Roots
. Hopefully it will happen early spring. I have verbal commitments from Billy Dee [Williams] to play my father, and Terrence Howard to play Smokey Robinson.
Who'll play you?
I'm not sure yet. Jennifer Hudson came to read for me. I also have an interest in Halle Berry
possibly doing it. And Fantasia.
Any of them would be great.
That's for sure! It really is exciting just to watch it all come to fruition.