After singing the chorus nine times in a row the worship team likes to kick it up a notch. Literally a notch, one step up from the key they were just in. The key change always occurs towards the end of a praise and worship song and signifies that the end is nigh.
Church-flavored drama sweeps the sanctuary. You might get goosebumps or nausea, depending on your personal resonance or baggage surrounding the whole church thing. The worship team is really getting into it now. Every eye closed, every expression pained! You may feel the key change was intended to work your emotions, and you may be right.