IN FEBRUARY OF THIS YEAR, Ariana Grande had the number-one, number-two, and number-three songs in America. So extreme a choke hold of the Billboard charts had only one antecedent: the Beatles achieved it in 1964, when “Can’t Buy Me Love,” “Twist and Shout,” and “Do You Want to Know a Secret” blanketed the airwaves. (Grande responded to the news of her pop preeminence in trademark terse, unpunctuated Twitterese: “wait what”.) But the singer, whose fame does not so much polarize as it sorts—into those who adore her, ape her high ponytail, and have made her the second-most-followed person on Instagram, behind the Portuguese soccer star Cristiano Ronaldo, and those for whom she barely registers (yet)—was in quiet knots. Thank U, Next, the album she wrote and recorded in a two-week fever dream the previous October, contained the most wrenchingly personal songs in her canon, and she was about to embark on a tour of at least 40 cities, where night after night she had to sing her way through a succession of private horrors.