(In second place was Brenda Lee’s Rockin’ Around the Christmas Tree with a comparatively paltry 193m plays.) In 2019 alone – when it reached No 1 in the Billboard chart 25 years after its release – it had 309m streams across all platforms in the US. It has risen up the UK and US singles charts faster than ever during the past two years as listeners reach for festivity amid the bleakness, resulting in startling figures: the first holiday song to be certified diamond (that’s above platinum) more than a billion streams on Spotify. It’s a song so big that it’s pretty much an industry all of its own. The first track on the first playlist is Mariah Carey’s All I Want for Christmas Is You. Spotify alone has 44 different options on its Seasonal Playlists page – leaving aside the vast number compiled by users – offering you hits, carols, punk, jazz, Disney and metal among many other genres. Christmas music has always done well – in Nick Hornby’s novel About a Boy, one of the characters lives off the royalties from a festive hit – but in the internet age it has assumed a new importance thanks to playlists on streaming platforms. This tactic has become bigger business than ever.