Plot: Oprah makes a special visit to the set of the hit television singing competition The Voice and sits down with all four coaches—Usher, Shakira, Blake Shelton and Adam Levine—who share their personal journeys as artists and how their lives have been affected by the show. Plus, Shakira discusses the challenges of motherhood, Usher shares how he learned to navigate the music industry at a young age, Blake opens up about his marriage to country superstar Miranda Lambert, and Adam reveals what he keeps in his bedroom