Lyric discussion by tikbalang 

Cover art for Let Robeson Sing lyrics by Manic Street Preachers

Paul Robeson had planned a trip to Cuba in 1961. Before then, however, he attemped suicide in a Moscow hotel room. His son contends that his father was victim of the CIA's MKULTRA experiments, and had been given a drug called BZ while there.

This is obviously a controversial topic, so confirming or debunking these statements I'll leave to those still interested.