Bay Psalm Book, first book published in the American colonies. It was prepared by New England clergymen, including Richard Mather and John Eliot, and was printed at Cambridge, Massachusetts Bay Colony, in 1640. It was the only work of its kind in New England churches for more than a century. The early editions gave no music, but the 1690 edition contained 12 tunes. The Bay Psalm Book is considered the most valuable of all American printed books because of its rarity and historical importance.