Five cops were shot and killed by a sniper at a Black Live Matter protest in Texas last Thursday, and in hopes of unifying the citizens of the city, Dallas Museum of Art's senior curator of contemporary art Gavin Delahunty called on Lennon's widow to help.

Longitme peace activist Ono offered up a work she created in 2001, which was inspired by the Beatles star's iconic song. The large white banner simply had the words "Imagine Peace" printed on it in black lettering, but she decided to add "Forever" on the end as an update for the Dallas tribute.

The simple message is also printed in Spanish, and hanging in the museum's Ross Avenue Plaza until 22 August (16).

A statement from the museum reads: "The Dallas Museum of Art hopes to inspire individual empowerment, as Ono profoundly believes we all have the power to create positive difference in the world."