Belinda Carlisle, the voice behind the '80s pop group Go-Go's, bared all in December for a Playboy photo shoot, which will be featured in the magazine's August issue. The singer told ABC's Good Morning America that the pictures were a homage to the Vargas style of the '50s pinup. "You don't have to be age 20 and size zero to be … sexually viable or viable as a woman," Carlisle, 42, said. "And that's part of the point that I would like or we all like to prove anyway." The Go-Go's released their first album of new material since 1990 last week and will promote the album this summer with an U.S. tour.