The black and white artwork features many famous faces including Billy Connolly, Gerry Rafferty and Jimmy Reid.
Art Pistol - a platform designed to help up-and-coming artists - has taken charge of the project, with Bob McNamara (a.k.a Rogue One) and Danny McDermott, known as EJEK are among the artists working on the mural.
McDermott and McNamara will eventually cover both sides of the pub with paintings of famous faces who drank in the bar or performed there in the past.
Bar owner Alan Crossan is re-opening the bar in stages, following the devastating helicopter crash on 29 November 2013, in which ten people lost their lives.
The mural will be covered up before the bar is reopened later this month.
Ali Smith of Art Pistol told the Evening Times: “We are honoured to be working on this and we really hope people enjoy seeing all the faces. We’d have liked to have had even more characters but there’s only so much space.
“We can’t wait to unveil it - this is just a sneak peek of what’s to come.”
Mural left to right: Spike Milligan, Billy Connolly, Gerry Rafferty, Alex Harvey, Frank Zappa, Jimmy Reid, John Martyn, Glenda Jackson, Rupert Everett.