Hymnology (from Greek ὕμνος hymnos, "song of praise" and -λογία -logia, "study of") is the scholarly study of religious song, or the hymn, in its many aspects, with particular focus on choral and song. It may be more or less clearly distinguished from hymnody, the creation and practice of such song. Hymnologists, such as Erik Routley, may study the history and origins of hymns and of traditions of sung worship, the biographies of the women and men who have written hymns that have passed into choral or congregational use, the interrelationships between text and tune, the historical processes, both folk and redactional, that have changed hymn texts and hymn tunes over time, and the sociopolitical, theological and aesthetic arguments concerning various styles of sung worship.