How Church Worship Corrupted - Authentic Expression or God Speaking?

God speaks, and we respond to the voice of God in the Word. But worship today is configured as authentic expression or an emotional experience. What is Biblical worship? Is it a formal liturgy or the informal guy in the t-shirt and tennis shoes having a conversation with us from the front of the stage? Can rejoicing and reverence be complementary in worship? Why is psalm singing so essential to the worship of the church today?