The world famous carol service from King's College in Cambridge will be performed without a congregation for the first time in its history - but will still be broadcast around the world as the choir's Christmas "gift to others".
Sky News was given exclusive access to film the King's College choristers during their final rehearsals for the Festival of Nine Lessons and Carols.
The service has come to symbolise the start of Christmas for many around the world.
It is estimated that up to 100 million people listen to both the live radio broadcast at 3pm on Christmas Eve and the recording of the carol service which is played across the globe, including on more than 450 public radio stations in America.
The 16 boy choristers, aged between nine and 13 years, and the 14 male undergraduates who make up the choir have been described as being like elite athletes of the singing world.
Like other top performers, they were forced to do their usual daily routine of rehearsals online for part of this year because of COVID-19.
But the choristers told us it hadn't taken away any of the excitement.
Twelve-year-old Leo said: "Every year it's really something special, it's exciting and also it makes you really nervous, because next week we'll be recording a service which goes all around the world and it's really something incredible that we get to do."
He added: "At the same time the Christmas music that we sing is really so amazing and it's such a nice thing to be able to do".
While Oliver, who's eight said: "It's just amazing because it's a once in a lifetime opportunity, and not many people get to do this.
"So it just feels amazing. I've always loved singing, even since when I was in year 2, I've always been singing, so I just knew I just wanted to do this."
The young choristers can now sing together, but the men do have to stand two metres apart, bringing challenges for musical director Daniel Hyde because it changes the way the singers are able to hear each other.
But he told Sky News the pandemic had in many ways made them more thankful that they can share this experience.
He said: "What the situation has reminded me of is just how we worry all the time about performance and perfection and the detail of what we're doing but actually we sort of take for granted the fact that we are coming together to do it..."
"...and when we couldn't do that we realised how much that social and indeed that sort of team work aspect we all missed."
Getting in to see the Festival of Nine Lesson and Carols is one of the hottest tickets around, with people usually queuing through the night to get a seat.
But the COVID-19 pandemic means there won't be a congregation this year.
The first service was held in 1918 and through his research the Dean of the chapel, Stephen Cherry, found it had never happened without a congregation before - not even during the Second World War.
During this period the audience were given an evacuation plan in case they needed to leave the chapel quickly.
He said: "It's kind of interesting really that my mind went straight back to the wartime experience, thinking that was the last time, there was a crisis of the kind that might have caused that to happen, otherwise it would be off the map."
Mr Cherry added: "It's fundamental that this is a service of hospitality, it's always been a gift to others, not just for the college and it's really wonderful that we can give it through broadcasting now."
Despite the pandemic, the service will contain many of the elements that viewers and listeners have come to expect.
That includes the tradition where the choristers are only told at the very last minute on Christmas Eve who will sing the opening solo of Once in Royal David's City and start the most famous carol service in the world.
