Both of these "styles" are represented in Psalm 95. In fact, two contemporary worship songs have been composed from this psalm, each reflecting one of these styles. The psalm begins with a call to worship that is very upbeat. We are called to sing to the Lord, to make a joyful noise to him and to come into his presence with thanksgiving. The basis for this is what he has done--he is a great God, a great King, who has created the world.
The psalm continues with a change of tone, as a more reflective tone comes in. Worship moves from being strictly upbeat as we remember all that God has done to reflection as we meditate upon our status before our King. We worship him and bow down before, submitting ourselves to our God, who is our shepherd. We are the people of his pasture. He cares for us.
In our lives, it is easy to recall the splendor, glory and majesty of God as we take in creation around us--the tranquility of an unbroken snowfall, the power of a forceful thunderstorm, the peace and quiet of a wilderness lake, the hope and promise of early spring. It is not so easy to remember, in our busyness, the pastoral care of God as he seeks to shepherd us, his sheep.
For this reason, the psalm concludes with a warning: "Today, if you hear his voice, do not harden your hearts." The warning reminds us of the Israelites, who were accustomed to remembering the big picture of redemption in joyous celebration but often forgot the care of God in their lives. This led to grumbling and complaining that displeased God. Ultimately, the psalm reminds, us, they did not enter God's rest. They fell in the wilderness. The warning is to watch over our hearts so they do not become hardened to the voice of God that we hear in worship.
Worship that is biblical moves between joyous celebration and humble repentance. God's voice is always speaking to us and calling us. But when we hear it, will we harden our hearts and put God to the test? Or will we submit to him in obedience?