When Adam Levine told Tonya Boyd-Cannon she’d have to perform Elton John’s “Take Me to the Pilot” on the “Live” segment of NBC’s talent competition The Voice, she cried. It wasn’t a lack of fortitude—toughness was a prerequisite for her former position as a sheriff’s deputy in the Orleans Parish Prison. Her struggle wasn’t about technical challenges, either. She just couldn’t make it work. She tried praying, meditating, doing yoga … still, nothing. “Why would Adam do this to me?” s<...