This story has been reproduced from today's media. It does not necessarily represent the position of Liverpool Football Club.
Guy Chambers, the producer of the Hillsborough charity single He Ain't Heavy He's My Brother, says working alongside Paul McCartney was like winning a golden ticket.
The triple Ivor Novello winning producer, who has penned tracks for the likes of Kylie Minogue and Rufus Wainright, said the experience was up there with performing at Glastonbury with Robbie Williams.
The Hillsborough charity single, which has already smashed through the 100,000 pre-orders mark, is a cover of The Hollies' He Ain't Heavy He's My Brother, goes on sale on December 17 with the aim of making it Christmas number one.
The record by the Justice Collective aims to raise money for the fight for justice for the 96 who lost their lives in the 1989 disaster. Ahead of it's release, Guy said: "I was asked to do it by Keith (Mullen) from the Farm when I was up at LIPA doing a masterclass.
There was an initial list (of musicians) which included (The Clash's) Mick Jones, John Power and Gerry Marsden, I think.
And then I thought that it would be something that Robbie (Williams) would get into so I sent him a short mail and he said 'yes' almost immediately.
Once he said yes, plenty of other people signed up."
On working with Sir Paul McCartney, he said: "Spending a day with Paul at his home studio was like winning the golden ticket.
He was unbelievably cool and accommodating, and took direction from me very gracefully.
It was definitely up there with playing Glastonbury with Robbie!"