We all know that Ed Sheeran wrote 'When Christmas Comes Around' for X Factor winner Matt Terry, but Framlingham's finest has been writing songs for other artists for years, and they don't all sound like his trademark folksy pop.
These seven songs were all written or co-written by Sheeran, and if you thought you weren't a fan, these might make you think again…
1. 'COLD WATER' by Major Lazer feat Justin Bieber and Mø
One 2016's defining summer jams, there's a lot going on in 'Cold Water' – it's another collab between Diplo and Justin Bieber, it features Danish electropop singer-songwriter Mø, and there's also that Gucci Mane remix to take into account – so you'd be forgiven for not suspecting Sheeran was involved. But check the songwriting credits and there he is.
He didn't write it alone, though. In total there are seven songwriters credited, including producer Benny Blanco and frequent 1D collaborator Jamie Scott, but once you know Sheeran's in the mix, it's impossible to unhear his influence.
2. 'LOVE SHINE DOWN' by Olly Murs
Tucked away on Olly Murs's 2010 self-titled debut album is this ska-influenced and sweetly forgettable love song. Both Murs and Sheeran have done far better since, but that's kind why 'Love Shine Down' is worth a listen: it'll make you appreciate how far both stars have come, but also how well-defined their styles were right from the f. The lyrics are classic Sheeran: "You're the battery to my heart/And without you I can't start/Don't you leave me in the dark" is the kind mundane hyperbole that never works as well on paper as it does when he's singing it.
3. 'TATTOO' by Hilary Duff
This one is probably less a "song you didn't know Ed Sheeran wrote" and more a "song you didn't know at all", because who knew former Disney ingénue Hilary Duff was still making music? At one point, 'Tattoo' was set to be the promo single for Duff's 2015 album Breathe In. Breathe Out., but she went with 'Chasing The Sun' instead. Which is a shame, because while that track now sounds hopelessly dated, 'Tattoo' still sounds like it could end up on a lower-tier supermarket's Christmas advert.
Knowing who wrote it does change the meaning the song a bit, though; when Duff sings tattoos left by a former love, it sounds metaphorical, but once you know Sheeran's involved, you've got to suspect it's meant entirely literally.
4. 'LAY IT ALL ON ME' by Rudimental