I attended a fascinating shiur by R' Menachem Leibtag at RIETS' Kollel Yom Rishon on Armistice Day in 2007, on the Biblical roots of Pesukei Dezimra. He focussed on Hodu, how the passage from I Chron is a paraphrase of two tehillim.
Enroute, we analyzed Psalm 105, the beginning of which is paraphrased in Hodu. R' Leibtag has a simple approach to breaking down a psalm:
3) What's The Point.
Here's the psalm, broken down as it was done in class.
vv. 1-5 are a command, telling someone to praise God.
6: who is to praise? The descendents of Avraham and Yaakov, namely, us.
v. 7: what is the object of the praise? God, who rules throughout the land.
So we have subject (we), verb (praise), and object (God).
Note that verse 7 calls Him "Elokeinu", where v. 1 calls Him "YKVK" - the object of praise is in an intimate, I-Thou relationship, not the transcendent Commander God, King over all the nations. We who are in a covenantal relationship with God, we praise Him.
Let's break down the rest of the story:
7: declares God as the Party of the First Part in the covenant..
8 sets the tone of remembering the Covenant. Which Covenant?
9-11: The Covenant Between Halves, with Avraham, that his descendents will wander, will go to an alien land, will become enslaved, and after 400 years will emerge with great property and return to Kena’an (Israel). The promise of having a nation some time in the future.
12-15 There will first be a period of wandering.What period of wandering is referred to the Psalm, where God didn’t let people touch us? The period of the Fathers:
16-22: concluding with the final journey to
23: we arrive in
24: we’re doing OK
25: not so much any more.
26:Moshe and Aaron are sent
27 and convince Paroh and the Jews with their magickal Signs and Wonders.
28-36: The Plagues come down to convince Paroh - frogs, blood, locusts, darkness, killing the firstborn, etc.
37: and sure enough, we are sent out with gold and silver.
39-41: the Desert experience: pillars of fire and smoke, Manna, crossing the Sea
42: and God finally fulfills the prophecy, the covenant with Avraham:
43-44: by bringing us into the Land, conquering the inhabitants – the Fifth Cup, but why?
45: So that we could fulfill the Torah and its Mitzvot, live our true destiny as god’s people, and praise Him. And that’s our end of the Covenant – when God keeps His covenant, it is our duty to say Hallel.
When we say this psalm as part of Davening we stop after verse 15. (actually the slightly variant version from Chronicles), followed by the next bit, it becomes a more universal, perhaps post-Messianic message - Sing unto Him, all the Earth, the other nations shall remember His glory, etc. But the psalm itself in isolation may well have been an early version of Maggid. Which fits interestingly with the idea that King David composed the version of this psalm found in I Chron 16:8... as a liturgy to say over the daily offerings (see verse 7 - David ordained that the priests say the Hodu which follows while offering the daily sacrifices).
So perhaps King David then composed the alternate, longer version to use as a Maggid at the Pesach seder. That would liturgically link the Pesach offering with other Temple rituals, emphasizing that the culmination of the Exodus was the Temple in Jerusalem, where we could (and will bb"a) fulfill all the mitzvot of the Torah.