​For example, in “Hey Jude,” everyone will begin to sing the “Naaaa… Na Na- Na Na Na Naaa” part very loudly at the end. Enemies will actually turn into friends during this part. Nations at war will literally lay down their arms and hold hands just so they can sing the “Na Na Na” part together. Hooks, in this respect, can be used in peacekeeping tactics.

At rock concerts people will “flick their Bic,” or hold up their lit cellphones, when the band plays a hit. It’s a sign of great respect, and connects people of all ages: adults, children, and even the guys smoking weed in the middle row.