There are several watercooler moments in British pop music; Geri Halliwell quitting Spice Girls, Alexandra Burke duetting with Beyoncé on The X Factor Live Final...and a fan-organised campaign ending in Rage Against The Machine beating Joe McElderry to 2009's Christmas Number 1.
First, a little context. By 2009, The X Factor was the biggest television show in the UK, reaching its peak cultural ubiquity. It was the prime-time Saturday night must-see, creating chart-topping careers for (at that point) Leona Lewis, Alexandra Burke and JLS, as well as helping judge Cheryl Cole assume superstar status in her solo career (although perhaps the programme's greatest achievements, the creation of One Direction and Little Mix were yet to come).
By 2009, The X Factor had accounted for the last four years of the UK's Official Christmas Number 1s; with the winner's singles from Shayne Ward (That's My Goal, 2005), Leona Lewis (A Moment Like This, 2006), Leon Jackson (When You Believe, 2007) and Alexandra Burke (Hallelujah, 2008) all reaching the festive top spot.
Clearly, some people thought it was time for a change, and for The X Factor's seeming monopoly on the Christmas Number 1 title to end. There had been several grassroots campaigns to un-seat Alexandra Burke's gospel take on Hallelujah by pushing Jeff Buckley's hallowed cover of the Leonard Cohen classic to Number 1, but they didn't come to fruition.
MORE: Rage Against The Machine's Official Charts history in full
Cut to the final of The X Factor 2009. Geordie Joe McElderry had surged to victory with a cover of Miley Cyrus' The Climb. but a question mark still hung over whether he could carry on the legacy and secure a fifth consecutive Christmas Number 1 for the Syco cohort. Enter Jon and Tracy Morter.
The duo had tried in vain the previous year to Rick Roll the nation with a passionate campaign to get Rick Astley's Never Gonna Give You Up to Number 1. But for their next trick, they zoned in on a guttural rap-rock protest song, hardcore American rock band Rage Against The Machine's Killing In The Name.
This was nothing personal to Joe McElderry either, with the campaign sowing its roots well before he had even been crowned victor, but suddenly the Official Christmas Number 1 for 2009 was comprised of a two-horse race; a fresh-faced wannabe pop idol and a track that mixed rap, alternative rock and hardcore metal that had reached Number 25 during its original 1992 release.
Making full use of burgeoning social media platforms such as Facebook, the Morters succeeded in running one of the first truly viral campaigns; that spread from online forums to quickly being plastered all over the news.
And it turns out, all the publicity paid off. Rage Against The Machine's Killing In The Name re-entered the UK Official Singles Chart at Number 1 on the week commencing December 20 2009, netting them the Official Christmas Number 1 in the process.
Killing In The Name pulled together a mightily impressive 502,000 copies in seven days, while Joe wasn't actually that far behind, debuting at Number 2 with 450,000.
According to Official Charts Company data, Killing In The Name has UK chart sales totalling 1.4 million, including 809,000 digital downloads and a very impressive 72 million streams. The Climb somewhat lags behind with 859,000 chart sales, although with 443,000 physical sales, it's the most-physically purchased of the two.