Adele's 2011 blockbuster, 21, was all about turning pain into power. Four years and 30 million albums sold later, remorse is still her muse. But where 21 was the sound of a woman soldiering through bad romance, 25 finds her queenly and resolute, lamenting the past on songs with titles like "Water Under the Bridge" and "When We Were Young." Even "Hello" is a goodbye. The nostalgic mood is the perfect fit for an artist who reaches back decades for her influences, even as her all-or-nothing urgency feels utterly modern.