The 90-second film, which was written and directed by Sony Bravia 'balls' creative director Juan Cabral of Fallon London, launches during the 'Big Brother' final tomorrow night.
The campaign will run throughout the Autumn and also includes outdoor, print, a digital campaign from Hyper, PR support from Sputnik Communications and sponsorship.
The ad begins with the first bars of 'In the Air Tonight' as the camera slowly pans across until a mysterious figure is revealed -- a gorilla sitting at a drum kit.
As the drum solo kicks in, the gorilla starts drumming in perfect time with a look of concentration and passion on his face.
Phil Collins said: "The gorilla's not as good a drummer as me but he's got more hair, I'll give him that."
Gorilla is the first execution from A Glass and a Half Full Productions, a platform created by Cadbury to showcase "exceptional pieces of entertainment". A 10-second version of the film will be aired in October
Lee Rolston, head of marketing for Cadbury Dairy Milk, said: "The campaign represents a real gear shift for the brand, not only in the level of expenditure -- the highest for any Cadbury chocolate bar for five years -- but in the level of creativity."
Laurence Green, partner at Fallon London, said: "This is a brand the nation has a massive soft spot for, with equities to die for."
Fallon picked up the Dairy Milk business earlier this year, as exclusively reported by Brand Republic.