Many of the psalms have no author attributed to them, so we have a large group of ‘unallocated’ psalms that have no identified author.
Psalm 117 is the shortest of all the Psalms and beautiful in its simplicity:
Praise the Lord, all you nations!
Extol him, all you peoples!
For great is his steadfast love toward us,
and the faithfulness of the Lord endures forever.
Praise the Lord!