With a gritty, soulful set of pipes well beyond her years, singer/songwriter Elle King exploded into view in 2014 with her international smash “Ex’s & Oh’s,” establishing a sound simultaneously rootsy and modern. King soaked up old-school rock, R&B, and country influences early on, and she freely blends banjo and Bo Diddley beats—and disco, alongside Miranda Lambert on “Drunk (And I Don’t Wanna Go Home)”—while rocking out amid the bluesy guitar licks of “Good Girls” with equal assurance.