A Hillsborough charity single which is aiming to become the UK's Christmas No.1 was played for the very first time at Liverpool's St George's Hall on Thursday morning as it was announced another global superstar will feature on the track.
'He Ain't Heavy, He's My Brother' was played to the families of the 96 who died at Hillsborough as well as those who have helped campaign for justice.
And it was confirmed that Sir Paul McCartney will feature on the single, with the former Beatle performing a guitar solo.
"Paul McCartney is one of - if not the - most famous sons of Liverpool, so to get him involved is fantastic," said Peter Hooton.
"We had to keep it a secret. He only recorded it a couple of days ago and it's a very Beatles-esque guitar solo. Getting him involved was the icing on the cake, really.
"It's not just about selling records, it's about awareness and when families come together at Christmas, this song with sentiment - this song that means something - will be in their living rooms."
The cover of the Hollies' classic is produced by Guy Chambers and as well as McCartney, it features a star-studded cast of musicians, including Robbie Williams, Paloma Faith, Mel C, Shane MacGowan, Mick Jones (The Clash), Pete Wylie (The Justice Tonight Band), Richard Hawley, Chris Sharrock (Oasis), Ren Harvieu, Dave McCabe (The Zutons), Paul Heaton (Beautiful South), Hollie Cook, Jon McClure (Reverend & The Makers), John Power (Cast), Beverley Knight and Gerry Marsden (Gerry and the Pacemakers).
Also involved are Liverpool legends Kenny Dalglish and Alan Hansen, ex-Everton star Peter Reid, comedians John Bishop and Neil Fitzmaurice.
Organiser Steve Rotheram, MP for Walton, added: "It's an incredible day. We've produced something that will stand the test of time and is an improvement on an already beautiful record by the Hollies.
"The Justice Collective's version of 'He Ain't Heavy, He's My Brother' will be widely-received as a seminal piece of British music.
"We brought in experts from every single genre in the music industry - and they all did it for nothing. Nobody has been paid and there's been a great spirit and huge camaraderie during the whole process."
All artists involved are giving their time for free, and all proceeds from the sale of the single will go towards the Hillsborough families' legal costs in their fight for justice.
The emotional first airing of the track was met with huge applause.
Hillsborough Family Support Group chair Margaret Aspinall said: "It's very meaningful to me as an individual as it's the last record my son James bought me.
"When it was getting played, I could still see James handing me that record. I think he'll be so proud of everyone involved.
"Everybody on Merseyside will be absolutely delighted with it."
Hilda Hammond of the HFSG continued: "It's amazing that so many people were willing to do something like this. It shows the public awareness and that's what we've wanted for 23 years - the public to be educated and know what it's all about.
"Reaching No.1 is not the be all and end all, but it would be nice."
'He Ain't Heavy, He's My Brother' will be released on December 17. It's available for pre-order now via mobile at a cost of £1. Text 'justice' to 80010 to receive the track on its release date.