It’s only May, but “Drivers License” is already the song of the year. In the same vein as “Drivers License,” the ballads here tackle heartbreak with grace — even when she’s parting ways with an ex, she resists the urge to tear their new partner down. “She probably gives you butterflies.”Just like she did with Billy Joel on the hypnotic “Deja Vu,” Rodrigo brings old musical references back into our consciousness, like an excited teenager relaying gossip on a rotary phone. Popular on Rolling StoneRodrigo wades through Sour free of any pretenses or protection, reveling in her insecurity and weaknesses. But she’s forging a path into an entirely new realm of pop, where she’s unapologetically and enthusiastically her own guide.