Roger Waters says that he has a concept that ties his next record together which asks, "Why are we killing the children?"

"I have made an entire demo," Waters told Yahoo! Music.

"I'm in a room sitting with a guitar, all the demo recordings and a legal pad and a pen, shoveling things around and scribbling things down.

It's an attempt to come up with a shape, a cartoon sketch of what this painting may be when it's finished."

"Why change now?" he replied when asked if the new songs will form a concept album. He also revealed that "the basic question of the album is, 'Why are we killing the children?'"

Waters added that there is no timetable for the album's release.

"The difficult bit in any project like this is getting the first sketches and finding the basic shape of the thing, blocking it out into the gray bits and the white bits."