Indie darling Mitski asks herself, ‘now what?’

Cult pop sensation Mitski is poised on the brink of mainstream stardom. The 31-year-old Japanese-American musician occupies a rare and coveted artistic space: independent, and beloved by fans and critics alike. But there is nothing simple about the musical career she has created—and to make it all work has required a careful balance to maintain a sane headspace between the intensity of her fame and learning to live, work and maintain creativity. Christopher Booker reports.

After so many years, shows, and questions about his relationship with his on again-off again musical partner, Art Garfunkel is telling his side of his story....