The Grammy and Oscar winner will also write an original song for the production, called Turn Me Loose, starring Scandal star Joe Morton.

Written by Gretchen Law, the play will centre on Gregory, whose 1960s stand-up comedy routine about the absurdity of racism led to him becoming an influential activist, working for equality with the likes of Martin Luther King Jr. and Medgar Evers, among others.

Legend praises Gregory and his legacy in a statement which reads: "People like DICk Gregory, Paul Robeson, Harry Belafonte and Nina Simone show me what the definition of an artist is - it isn’t just to make art but to speak truth to what’s happening, speak beauty into the world, speak love into the world and also get involved."

The R&B star has found success as a producer with his Get Lifted Film Company over the past year - he's currently behind new TV slavery drama Underground, as well as a new stage show, 3 Mics, featuring comedian Neal Brennan.

Turn Me Loose opens on 3 May (16) at New York's Westside Theater.