Seventy-three psalms carry the heading "le-David" — "of David," "belonging to David," "in the manner of David." The historical David is the dynastic founder of Jerusalem; the David of the Psalter is the type of the king who prays in every condition, including the condition of having sinned. Psalm 51, the great penitential psalm, carries the superscription "when Nathan the prophet came unto him, after he had gone in to Bath-sheba." Whether he composed it or not, the connection is theological, not just biographical.
Psalms — who's who
The Psalter — voices of Israel's prayer.
The Psalms do not have characters in the narrative sense. They have voices — recurring types of speaker whose situations recur across the collection. These are the six voices that between them account for most of the Psalter's range.
The attributed voices
Twelve psalms are attributed to Asaph, the head of a Levitical guild of temple singers. The Asaph psalms dominate Book 3 (73–89), the darkest book of the Psalter. Psalm 73 — one of the great wisdom psalms — opens with near-apostasy ("as for me, my feet were almost gone") and resolves in an act of sustained trust. Asaph is the Psalter's most direct theologian of suffering, grappling most explicitly with the problem of the prosperity of the wicked and the silence of God.
Eleven psalms are attributed to the sons of Korah, another Levitical guild of temple singers. Their psalms — concentrated in Books II and III — include some of the most celebrated in the collection: Psalm 42–43 (as a deer pants for water), Psalm 46 (God is our refuge and strength), Psalm 84 (how lovely is thy tabernacle), Psalm 87 (glorious things of thee are spoken, O city of God). The Korahite collection has a distinctive intensity of longing for the temple and the presence of God.
Only one psalm is attributed to Moses: Psalm 90, which opens Book 4. "Lord, thou hast been our dwelling place in all generations. Before the mountains were brought forth, or ever thou hadst formed the earth and the world, even from everlasting to everlasting, thou art God." It is the oldest psalm in the collection and the one most directly concerned with the disproportion between human time — "a thousand years in thy sight are but as yesterday when it is past" — and divine eternity. The context of the wilderness wandering, in which Moses watched a whole generation die without reaching the land, gives the psalm its weight.
The structural voices
More than a third of the Psalter is lament. The form is consistent: address God by name, describe the trouble in vivid detail, complain — sometimes accuse God directly of abandonment — ask for deliverance, and almost always pivot to an act of trust or vow of thanksgiving before the deliverance has come. Psalm 22 is the most famous: "My God, my God, why hast thou forsaken me" opens it; "I will declare thy name unto my brethren" closes it. Psalm 88 is the only psalm that does not pivot — it ends in darkness, and the book includes it without apology.
The psalms that pray violent things against enemies. Modern liturgical practice has often quietly suppressed them; the book has not. The imprecatory voice commits its desire for vengeance to God rather than carrying it out — which is either the model of moral maturity or its failure, depending on the tradition one reads from. C. S. Lewis argued that the imprecations at least evidence genuine moral seriousness: the psalmist cares enough about justice to pray fiercely about it. The book records the voice without endorsing it theologically, and leaves the reader to reckon with what it means that prayer includes this.
The voice of the Davidic king — at coronation, marriage, battle, enthronement, and prayer. Contains the line most quoted in the New Testament: "The Lord said unto my Lord, Sit thou at my right hand" (Psalm 110:1). After the monarchy ended in 586 BCE the royal psalms continued to be sung in the second temple, their language increasingly read as the language of a king to come. The messianic expectation of late Second Temple Judaism, and the Christian reading of Jesus as that expected king, both depend textually on the Psalter's preservation of the royal voice beyond the monarchy's end.