Am I the only one who thinks "Birthday" sounds like "Last Friday Night"? That does not mean it won't smash if it's released as single. She has to release "Dark Horse" after "Unconditionally" smashes.
I thought the same before the album leaked but now Birthday, Legendary Lovers (and Dark Horse ofc) are the best candidates for singles.
This Roar already hit #1, and Unconditionally looks like it's going to have a shot because it's had the biggest daily updates on airplay since reason. But after that these 3 songs you state above all seem like other possible #1's
Am I the only one who thinks "Birthday" sounds like "Last Friday Night"? That does not mean it won't smash if it's released as single. She has to release "Dark Horse" after "Unconditionally" smashes.
I feel like This is How We Do matches the theme of LFN, but Birthday has echoes of the instrumentals.
from 20% to 29% 
