Music·Updated on 28 Sep 2018. Posted on 12 Sep 201816 Singers Who Wrote Mega-Famous Songs For Other ArtistsBasically, Sia and Ed Sheeran wrote everything.by Jemima SkelleyLifestyle EditorFacebookPinterestTwitterMailLink 1. John Legend wrote "American Boy" Tap to play or pause GIF Tap to play or pause GIF youtube.com, Alberto E. Rodriguez / Getty Images I knew this track was iconic but I had no idea it was co-written by John Legend...and also will.i.am. 2. Pharrell Williams wrote "Hot In Herre" youtube.com, Dimitrios Kambouris / Getty Images I lowkey forgot all about Nelly and his bandaid, but I'll never forget this iconic tune. 3. Bebe Rexha wrote "Monster" youtube.com, Mike Coppola / Getty Images She co-wrote the 2013 song with Eminem and Rihanna, a year before releasing any of her own music. 4. Sia wrote "Diamonds" Tap to play or pause GIF Tap to play or pause GIF youtube.com, Pascal Le Segretain / Getty Images Sia's actually written and co-written a ton of iconic pop songs, like Camila Cabello's "Crying in the Club", Britney Spears' "Perfume", Beyoncé's "Pretty Hurts" and Katy Perry's "Chained To The Rhythm". 5. Jessie J wrote "Party In The USA" youtube.com, Leon Bennett / Getty Images Jessie was originally going to record it, but it was decided that it wasn't "edgy" enough for her. IDK how a Brit was going to sing about Nashville parties but oh well. 6. Katy Perry wrote "I Do Not Hook Up" youtube.com, Neilson Barnard / Getty Images Katy originally wrote it for her own album, but ended up giving it to Kelly Clarkson when she switched record labels. 7. Bruno Mars wrote "Forget You" Tap to play or pause GIF Tap to play or pause GIF youtube.com, Kevin Winter / Getty Images And remember when Gwyneth Paltrow sang it on Glee? A true pop culture moment. 8. Kesha wrote "Till The World Ends" Tap to play or pause GIF Tap to play or pause GIF youtube.com, Matt Winkelmeyer / Getty Images She said about the track: "I’ve never been more proud of anything in my career... It really solidifies me as a songwriter in the pop music world, which is what I consider myself first and foremost." 9. Ne-Yo wrote "Irreplaceable" Tap to play or pause GIF Tap to play or pause GIF youtube.com, Paras Griffin / Getty Images It was originally written as a country song, which is something I really need to hear. 10. P!nk wrote "Whataya Want From Me" youtube.com, Frederick M. Brown / Getty Images P!nk wrote it with Max Martin and Shellback for her Funhouse album, but it didn't make the cut. 11. Avril Lavigne wrote "Breakaway" youtube.com, Jon Kopaloff / Getty Images It was intended for Avril's album Let Go but didn't quite fit the vibe, so Kelly Clarkson recorded it for the Princess Diaries 2 soundtrack. 12. Christina Milian wrote "Baby" youtube.com, Frederick M. Brown / Getty Images Man, whatever happened to Christina Milian? 13. Prince wrote "Nothing Compares 2U" youtube.com, Kevork Djansezian / Getty Images It actually featured on an album from Prince's side project band, The Family, in 1985. 14. Jay-Z wrote Bugs Bunny's rap, "Buggin'" from Space Jam Warner Bros., Gustavo Caballero / Getty Images Featuring the iconic lyrics: "Like Trump's wife, up to my ears in carats (carrots) / Not even the barber can fade the rabbit." 15. Pharrell Williams wrote "Milkshake" youtube.com, Dimitrios Kambouris / Getty Images And it was originally offered to Britney Spears for her In The Zone album. 16. Ed Sheeran wrote "Strip That Down" youtube.com, Thomas Niedermueller / Getty Images I love the idea of Ed Sheeran sitting down and writing "I used to be in 1D, now I'm free". Ed's also written a bunch of other huge pop songs, like Bieber's "Love Yourself", 1D's "Little Things" and Major Lazer's "Cold Water".