'Perfect Illusion' shows Lady Gaga has rediscovered her mojo

Let's not bother with a poker face here. Released late Thursday, "Perfect Illusion" is a stomping disco-rock jam with a killer robot-Motown groove, buckets of scuzz-punk guitar fuzz and a key change designed to trigger Pavlovian fist-pumps. It has a melody that will burrow into your brain before the 2-minute mark. And like all the best pop songs, it can't decide if it's sad or happy, paranoid or ecstatic; the tune lifts you up at the same time that it marches over you, a blast of serotonin under constant threat of reuptake. "I don't need eyes to see / I felt you touching me," Lady Gaga sings, her voice fraying at the edges.