“Rejoice in Yahweh!
O you righteous!
Praise befits the upright.
Praise Yahweh with the lyre!
Make melody to him
With the harp of ten strings!
Sing to him a new song!
Play skillfully on the strings
With loud shouts.”
There is nothing here about this Psalm 33 that indicates that it came from David since there is no introduction to this psalm at all. This clearly is a Temple hymn, a call to worship Yahweh. The righteous were to rejoice in Yahweh. They should offer praise that befits an upright people. They were to praise Yahweh with the lyre, an ancient horseshoe shaped frame with strings. They were to make a melody to Yahweh. They were to use a ten stringed harp. They were to sing a new song. They were to play on the strings skillfully, not in a sloppy manner. Finally they had the loud shouts, like the shouts for war, as Yahweh would lead them on to victory.
Eugene Finnegan Bible Project 