The Vaccines' frontman, Justin Young, has written tracks for One Direction for their forthcoming album.
Young swapped rock for pop last month to write and record new material with the boy band for their new album and says he enjoyed every minute of his collaboration with the X Factor stars.
Speaking to BBC Newsbeat, he said: "It was a really interesting creative process, writing with pretty much the biggest pop band on the planet. It was a very different world and very different process - that was one of the reasons I wanted to do it. I really enjoyed it. I felt like I took so much from doing it.
"I've always said I love pop music and how much I want to write pop music. It's the first time I've ever done anything like that. They do indeed contribute (to the song-writing process)."