In this verse, David says to make music for the Lord because he is the God who saves. David was a skillful musician. In 1 Samuel 16:14–23 we read about his talents for the first time. The book of Psalms bears witness to this, and we read about this long after David’s death (in Ezra 3:10 and Nehemiah 12:24, Nehemiah 12:36, and Nehemiah 12:46).
9 I will sing a new song to you, O God; upon a ten-stringed harp I will play to you,