In just a few hours time, Crystal Palace will take on Manchester United in the FA Cup final. But they aren't the only London success story to hit Wembley today - as the Lewisham and Greenwich NHS Choir perform in front of thousands at their biggest ever live gig.
This Christmas, the choir became a global sensation after beating Justin Bieber to the number one spot. And they've gone from strength to strength since - arriving at Wembley today to perform alongside Bieber himself.
"The ladies are in there dancing to Bieber and Tinie Tempah right now!" consulant Chidi Ejimofo told ITV News from the stadium just a few minutes ago. "We're just trying not to get too excited so we don't ruin our voices!"
Mr Ejimofo, who sings in the choir when he isn't at his day job as an A&E consultant at Lewisham Hospital, said he can't believe the success the choir have had over the past few months. "It's been totally surreal" he said. "The tide of goodwill behind us had just seen our profile grow. I think people appreciate the fact that we just are normal people, and the choir is a passion not our main job. We're still delighted to be playing small local gigs because we just love singing."
He said the choir were contacted on Twitter initially about the FA Cup gig. "It's been a whirlwind since we got the booking. Today has been planned with military precision, we've been in rehearsals all day and doing sound checks, and we've got our own dressing room. Everybody is just so excited. It will be the biggest live audience we've had by a mile"
The choir will be performing the hymm "Abide With Me" with the Welsh Guards, and will also be accompanying fellow Londoner Tinie Tempah on one of his songs. Their new single, Inside So Strong, is out on June 24th.