Cheryl launches new music, Taylor Swift takes her 'RED' tour to Japan, Jessie J debuts new music in Madrid and newlyweds Kim & Kanye step out in Prague.
"What I can say is that they're the hardest-working boys I've ever worked with. They still haven't changed. They're really respectful of their fans, they're a great British export, they've been a joy to work with. I've worked with a lot of artists in the past who do lose the plot, who do lose respect for their fans, they've never done that," Simon revealed to Digital Spy. Picture: PA