Hermann Gunkle and the History of Psalms

In the early 20th century, a German biblical scholar named Hermann Gunkle set out to classify all of the poems within the book of Psalms. He came up with five major categories for these individual Psalms: hymns, royal Psalms, communal and individual laments, and then the Thanksgiving Psalms. Now those five end up being whittled down to three, which is what most scholars talk about now. The content leads you to see that this is a Psalm singer praising Yahweh for who Yahweh is, what Yahweh has done.