Since winning “American Idol” in 2005, country singer Carrie Underwood has become one of the show's highest selling graduates, but she warned the latest crop of “Idol” finalists to “stay true” to their fans if they want to find similar success. Underwood will star next month in a holiday special, and she just released her second consecutive chart-topping album, “Play On.” As it happens, three finalists from this past season of top-rated US television show “American Idol,” a reality singing competition, are about to release their own albums. “I feel like any contestant that comes off ‘Idol' that does well on ‘Idol' has to stay true to what people voted for,” Underwood said, in response to a question. “I've seen it happen a few times where people are one thing on the show, and then they got off the show and try to do something else,” she said. Meanwhile, the four-time Grammy winner will star on Dec. 7 in a two-hour variety program called “Carrie Underwood: An All-Star Holiday Special,” on Fox.
