A new exhibition aims to bring Yoko Ono's art out of John Lennon's shadow

At London's Tate Modern, one of the exhibition rooms is devoted to 'Add Color (Refugee Boat)', a wooden boat painted white in a white-walled room. Markers are supplied for visitors to add words or images. Photo: AP

Before there was John and Yoko - and after - there was just Yoko Ono.

The Japanese-American artist became a global celebrity through her marriage to John Lennon, her partner for more than a decade until his murder in 1980, as well as her collaborator on peace-protest "bed-ins” and in the Plastic Ono Band.