Albert Barnes Commentary Psalms 105:2

"Sing unto him, sing praises unto him; Talk ye of all his marvelous works." — Psalms 105:2 (ASV)

Sing to him - Sing before him; offer him praise.

Sing psalms to him - The word here rendered “sing psalms” means properly “to prune,” and then, “to cut off,” as a discourse at regular periods; or, to utter in rhythmical numbers; and then it means to accompany such words with an instrument of music. The idea here is that he is to be approached, not merely with “singing,” but with sentiments expressed in the form of regular composition - in musical numbers.

You talk - The word used here very commonly means to meditate, to muse (compare the notes at Psalm 1:2), but would here seem to be employed in the sense of “talking over,” namely, in singing. That is, in the psalms used, let there be a “narrative” of what God has done. Let his works be the subject of the words used in the psalm.

Of all his wondrous works - Of what he has done that is suited to excite wonder and admiration. Compare Psalm 77:12.