Powerful voices full of emotion and moving intensity — that’s what comes to mind when we think of gospel music. And “Amazing Grace” is certainly one of the first songs we think of. It’s a song that spread beyond Christian churches to become famous as a protest song against slavery and as a hymn sung by human rights activists. “I once was lost, but now am found.” With the Christian idea of redemption, the song expresses a confident belief in liberation, the central theme of gospel music. But paradoxically, this song, which many people regard as the quintessence of American gospel music, was actually written by the former captain of a slave ship, John Newton. When he escaped from a storm at sea in 1748, he saw his salvation as divine providence and fundamentally transformed his life in the following years, after a while giving up his trade completely, becoming a clergyman, and even campaigning against slavery. His song, “Amazing Grace,” became extremely successful and was later adopted by the African-American spiritual and gospel community, performed by such artists as Mahalia Jackson, Aretha Franklin and the Harlem Gospel Choir.