If you are referring to the praise band stuff, it originated in revivalism. Which is to say that the atmosphere is created to induce an emotive response to the message and cause someone to make a decision for Jesus. It really is rooted in very bad theology, and it borders on idolatry, because it depends on the human effort to create an atmosphere that emotionally manipulates people into making a decision rather than depending the Holy Spirit who inhabits the Gospel to convict and convince and draw people to the Lord.