This immensely talented songwriter has quickly become a household name in the pop songwriting world. Credits on Maroon 5's "Don't Wanna Know", Pitbull's "Fireball", and Jason Derulo's "Wiggle" are just a few of the reasons. Perhaps the most notable is his longstanding work with British boy band, One Direction. If you've ever heard a One Direction song on the radio, you've most definitely heard this songwriter's handiwork. He has an astounding 39 One Directions cuts and has co-written all of the singles from their last three albums including “Drag Me Down”, "Best Song Ever", and "Story of My Life”. And The Writer Is...John Ryan!