The story behind one of the best-known hymns in the English language is the subject of the new Broadway musical "Amazing Grace." The show tells the story of the man who wrote, “I once was lost, but now am found; was blind, but now I see.”

John Newton worked in the English slave trade before changing his ways and becoming a spokesman for abolition in Great Britain — and a hymn writer. The production at the Nederlander Theatre features a score by Christopher Smith, a newcomer to musical theater, and a book by Smith and Arthur Giron. 

New York Times theater critic Charles Isherwood reviews it in this conversation.