This chapter contains not only some the narrative from the life of David, but also one of his psalms (compare to Psalm 105). In fact, the message of the psalm is the bulk and focus of this chapter.
David assigned certain priests and Levites to the tasks of taking care of the Ark and the Tabernacle. Keeping records, uttering thanksgiving and praise, singing and playing music... these were some of the various jobs that the holy men had as their responsibilities.
In celebration of the joyous occasion of the entrance of the Ark into Jerusalem... its permanent resting place... David gave everyone in attendance bread, meat and wine. And, he sent them home with a blessing and went to his own house with the intention of blessing his own family too.
That's the setting. Now, here is the gist of the psalm. "Thank God. Sing to Him. Worship Him. Meditate upon what He has done and what He has said. Tell God's enemies how great He is. Fear Him. And, trust in Him." Of course, that was certainly something that the people could agree with… and, they did (1st Chronicles 16:36).