Rachel Platten's career broke wide open with 2015's "Fight Song," a stirring adult contemporary power ballad that became an international Top Ten hit and was even adopted as Hillary Clinton's campaign song in 2016. Echoing such inspirational call-to-arms as Sara Bareilles' "Brave" and Katy Perry's "Roar," "Fight Song" became ubiquitous in the latter half of the 2010s, suggesting that Platten specialized only in ballads, an assumption disproven by its parent album, Wildfire, and its 2017 sequel, Waves. Both records showcased the fact that Platten didn't limit herself to ballads...