BBC Doctor Who Advent Calendar Day Twelve

With thirteen days until Christmas, the BBC's official website for Doctor Who was today updated with the twelfth door on their online Advent calendar. Inside today's door is a piece of unreleased music entitled 'The Wonder of Balloons' which was going to feature in last year's Doctor Who Christmas special, The Next Doctor, but never did. The music was composed by Murray Gold and can be seen inside today's door on the official Doctor Who website's online Advent calendar by clicking here. The thirteenth door on the calendar will be made openable tomorrow, and some details regarding that will be posted here, on The Gallifrey Vortex, shortly after the door is available to open. What are your thoughts on today's new surprise?