Yoko Ono turns 91 on February 18 and her pacifist and humanitarian actions are as valid today as when she launched the campaign against the Vietnam War while in bed with John Lennon. At the Tate Modern, graffiti "for the freedom of Palestine" and in solidarity with those who embark on boats covered the white background of the Refugee Boat installation.

The exhibition illuminates what "has been hidden because of being 'John Lennon's wife,'" according to curator Juliet Bingham. The academic highlights the nonagenarian artist's ability to "synthesize" the feelings and concerns of society with creative practices.