We're only a few weeks away from the Jan. 1 premiere of Pitch Perfect 3, but that doesn't mean we have to pass the time in silence. In addition to a pretty gorgeous "Cups" and "Freedom! '90" mash-up, we now have a glimpse at the Bellas going head to head with Ruby Rose's crew in a riff-off. Although they slay an a capella version of Pink's "Get the Party Started," the gang is not prepared for the rival group's take on Avicii's "Wake Me Up."