Shailene Woodley learned to sing “outside of the shower” while making a Janis Joplin biopic. The 32-year-old actress has revealed that she discovered the full extent of her singing talents while she was preparing to star in the upcoming biopic. Shailene said on ‘LIVE with Kelly and Mark’: “I’m not like a trained singer, but I feel and I can sing in my shower. “It turns out I can also sing outside of the shower, which I didn’t really know until I started working on the Janis project, and working with Linda Perry, who’s an amazing music producer and musician herself. “She’s really encouraged me …