Max Pearson presents a collection of the week's Witness History episodes.

We hear about the era-defining book Subway Art and how Fight the Power became a protest anthem. Artist curator Marianne Vosloo explains how both street art and hip-hop are linked.

Plus, two stories from Georgia. Firstly, how Stalin carried out his most severe purge in Georgia in 1937, killing thousands of people, and then how after the breakup of the Soviet Union in 1991, the newly independent state was thrown into a political and economic crisis.

Finally, we hear from a former Canadian prime minister, on how her party was left with just two seats after the election in 1993.

Contributors: Martha Cooper and Henry Chalfant – authors of Subway Art. Marianne Vosloo - artist curator who works within the field of street art and urban art intervention. Chuck D – Public Enemy frontman. Levan Pesvianidze – Georgian whose grandfather and uncle were both executed. Lamara Vashakidze - a survivor of Georgia’s crisis in 1991. Kim Campbell – former Canadian prime minister. Preston Manning – founder and former leader of Reform.

(Photo: People queing to buy Subway Art. Credit: Jemal Countess/Getty Images)