These feels like such a passionate psalm to me...I think that David probably sang it pretty loudly. And I can understand what he was feeling - searching for a way to humble himself before God, to be pure before the Creator of the world, who holds all in his hand and blesses those whose hearts love him. And then the ending...

Lift up your heads, O you gates;

be lifted up, you ancient doors,

that the King of Glory may come in.

For all of creation simply open up to the Lord, to the King of Glory. Let's let him in.