One of the most powerful ways to convey emotion is for the singer to
venture away from their comfortable range and make the listeners FEEL
the effort needed to hit those notes.
Zedd's "Clarity" is a magnificent composition top to bottom, but its emotional secret weapon is arguably the way Foxes uses her voice. Despite going up to a range where it's very difficult to do, Foxes sticks to her chest voice as she climbs up to new peaks.
Doing this builds up emotional intensity because it demands increasing (and audible) physical and emotional investment. And on top of that it goes hand in hand with the HUGE instrumental buildup.
Switching to head voice, which most vocalists would naturally do at that high range, would have sabotaged the buildup and stripped away its emotional power because it would sound 'too easy' in that context.
Zedd's "Clarity" is a magnificent composition top to bottom, but its emotional secret weapon is arguably the way Foxes uses her voice. Despite going up to a range where it's very difficult to do, Foxes sticks to her chest voice as she climbs up to new peaks.
Doing this builds up emotional intensity because it demands increasing (and audible) physical and emotional investment. And on top of that it goes hand in hand with the HUGE instrumental buildup.
Switching to head voice, which most vocalists would naturally do at that high range, would have sabotaged the buildup and stripped away its emotional power because it would sound 'too easy' in that context.