Gwen Stefani announced Friday that she is returning to NBC's singing competition series The Voice. The 52-year-old singer took to TikTok to reveal that she's returning to the show as a coach. She shared the news with a video that featured fellow Voice coaches John Legend and Blake Shelton, who is the pop star's husband. In the short video, the trio sang a portion of Mika's 2007 track, "Grace Kelly." ...