Music Demi Lovato Sings 'Let It Go' in Show-Stopping Live Performance By Antoinette Bueno 2:04 PM PST, December 10, 2014 YouTube Does it get any better than Demi Lovato singing Frozen's "Let It Go?" The 22-year-old belted out the now classic Disney tune at the annual Royal Variety Performance in London last month, though the footage only became available earlier this week. NEWS: Everything 'Frozen' That Happened in 2014Technically, the song isn't a cover, as Demi actually recorded an official version of the song for the film's soundtrack. But perhaps even more notable than Demi's predictably stellar vocals in the performance, is her show-stopping Ashi mullet-hem dress, which was adorned with feathers and a sparkly belt.... Looking good Demi!VIDEO: Kristen Bell Loves 'Frozen' Even More Than Your Kids Do ET was actually with Frozen stars Kristen Bell, Josh Gad and Idina Menzel last October, before the animated film became such a massive hit.Check out the video below to hear how the movie made Kristen's dream come true.