Psalm 47:7 - "For God is the King of all the earth: sing ye praises with understanding." - How are we to sing? With understanding. God is our AWESOME King & deserves nothing less than our best. When we sing without understanding whether we sing the old hymns in "vain repetition" or sing in such a way that no one can understand what is said i.e. "Christian" rock, we do not give God our best.Give God what He deserves.