Keith Richards is 70 now and a grandfather five times over, so maybe the idea of the Stones' guitarist writing a kids' book isn't as jarring as it once might have been. Richards is writing an homage to his own grandfather in Gus & Me: The Story of My Granddad and My First Guitar, reports the Guardian. As the title suggests, it's about how his grandfather, jazz musician Theodore Augustus Dupree, introduced him to music. Richards' daughter Theodora will do the illustrations for the book, which is due out in September. It follows the 2010 release of his autobiography, Life, notes CBS.