All she is saying, still, is give peace a chance AT 80, Yoko Ono looks like an ageless rock star in her skinny jeans, platform shoes, off-white fedora and funky sunglasses which apparently never come off. But the artist, who is presenting the first comprehensive survey of her work in Australia from today, is on a mission. The longtime peace activist and widow of John Lennon has titled her exhibition at Sydney's Museum of Contemporary Art War Is Over (If You Want It).