An in-depth history of the most important pop innovation of the last 20 years, from Cher’s “Believe” to Kanye West to Migos It happened exactly 36 seconds into the song—a glimpse of the shape of pop to come, a feel of the fabric of the future we now inhabit. The phrase “I can’t break through” turned crystalline, like the singer suddenly disappeared behind frosted glass. That sparkly special effect