Psalms 33:3

Sing unto him a new song
One newly composed on account of recent mercies received; and as the mercies of God are new every morning, there ought to be a daily song of praise to him; and so a new song is a continual song, as Christ is called the "new and living way", ( Hebrews 10:20 ) ; because he is the everliving way; or the constant and only one, which always was, is, and will be. Or it may denote some famous and excellent song, as a new name is an excellent name, an unknown and unspeakable one; see ( Revelation 2:17 ) ; compared with ( Revelation 14:2 Revelation 14:3 ) ; or respect may be had to the New Testament dispensation, in which old things are passed away, and all things become new; a new covenant is exhibited, a new and living way opened, and new ordinances instituted, and at the end of it there will be new heavens and a new earth; and so here is a new song made mention of, as suited to it;

play skilfully with a loud voice:
either with the quill upon the harp, and the instrument of ten strings; or with the fingers upon the psaltery, at the same time, vocally, and aloud, expressing the new song.