James Mays convincingly argues that the declaration "The Lord reigns" is not only a statement of faith but a statement of a particular that is, there is a God, and all of reality can be understood only in terms of God and God's sovereignty. By addressing the importance of the language associated with the reign of God as expressed in the Psalms, The Lord Reigns offers a way to better understand the relationship between God and creation.
At times, Mays' book veers into "must read" territory, but the somewhat repetitious nature of the work keeps it from that category. A very good resource on the theology of the psalms.