Just a quick note - Psalms 74-75 are pretty much in the middle of the psalter. I began this project considering how the writer to the Hebrews uses the psalms as major parts of the dialogue between the Father and the Son. Psalms 74 and 75 are like a dialogue between the (anointed) psalmist and God. But what a dialogue this represents with the explicit and grammatically unnecessary use of אַתָּה in 74 (and 76) and of אֲנִי in 75 (and 73). Is it possible that the theme of the Psalter is more than praise? Perhaps it is better named as the preparation of God's Anointed through history, proleptic but not necessarily identical with the Anointed Jesus who was yet to come, and the Psalter read as a book of instruction provides us who come after with insight into that same anointing dialogue. (I am also searching for a reframing of the word Christ. I think Christians take it too much for granted.)
Related posts on 'theme' of the Psalter: here, here, and here. Also the book by Robert Cole that Richard pointed out last March. I really must read this one.