christian music has diversified over the time, reflecting both its centuries old roots as well as more contemporary musical styles. thousands of traditionally-styled songs of praise or worship, called "hymns" (from the greek word "hymnos" meaning, "song of praise"), were written over hundreds of years. eventually, these songs were compiled into books called "hymnals," from which pastors and congregants would read during christian services - a practice that continues in many churches today.