Diana Ross told David Letterman that she will be featured on the sixth season of American Idol-as a “mentor.”

“I’m going to do the ‘American Idol,’ as a mentor. And then I’ll leave from there and I’ll go on tour, March and April,” the “Supreme” singer told D.L. No word on this from the execs over at Idol.

Lady Di still has that “Dreamgirls” chip on her shoulder, though. “Yes, I’ve heard a lot about it. I’m going to see it with my lawyers.” The original musical, as well as both film adaptions of the Golden Globe award-winning film, are based on the experiences of girl groups in the sixties-the title group is loosely based on the Supremes.