What is meant by exclusive psalmody? Only the book of psalms? Other psalms and inspired songs from the Bible also (Revelation 5 and 15, Miriam at the Red Sea, Zacharias, Mary, and the like)? How about scripture set to music that was not originally written to be sung--such as the Lord's Prayer and Handel's Messiah? Also, does EP only apply to Lord's Day morning worship or to all worship, private as well as church body?