Amazing Grace: The Story of America's Most Beloved Song, by Steve Turner. Ecco / HarperCollins, 304 pages, $23.95.

The words were written in 1772 by John Newton, an English slave trader, and set to its presently familiar tune by William Walker, a South Carolina singing instructor, in 1835. Since 1970, more than 450 separate recordings of the song -- now pop platinum -- have gone on the market. How that all came about is the tale laboriously researched and then captivating told by Turner, a first-rate musical historian. It's high drama -- shipwrecks, African servitude, spontaneous religious conversion and through it all, deep spiritual experience. This is a book that reads like a thriller, moves one like a revelation and graces history with wit and insight and celebration of genius. Unforgettable.