they talk more here forbes*com/sites/dannyross1/2017/10/26/one-direction-hit-makers-climb-charts-with-slow-hands/
ooh, this WAS a good read!! I liked this bit in particular,
Ross: I thought the end of the chorus was cool because Niall’s vocal melody doesn’t resolve.
Bunetta: Exactly! And it makes you want to hear it again. A music teacher told me a story of how Mozart’s wife would get him out of bed by going like this [playing a scale without resolving to the tonic note]. Having that suspension keeps you waiting.
just because it kind of gave words to that feeling? like, you certainly FEEL like there must be something coming, but it was really cool to have that pointed out and explained! the rest of the article had some pretty interesting bits and pieces too, like most top 100 Spotify songs being three or four chords on a loop. that you can DEFINITELY hear, too, and maybe not in the best ways?