Starbucks is undertaking the biggest global Facebook ad campaign to date to raise awareness of the project, which it says is a celebration of its partnership with (RED), the charity that fights Aids in Africa.
The campaign promotes this Monday's global singalong, which gets underway at 1.30pm GMT on 7 December and can be seen at a dedicated website, .
Starbucks has invited a number of musicians around the world to perform the song simultaneously, which will be filmed and streamed to the website.
Following the singalong, everyone with access to the site and a video camera will have the opportunity to submit their own version of the song. For each video that is contributed to the site, Starbucks will make a contribution to the Global Fund.
From tomorrow, Facebook users in the US, UK, Canada, Turkey, France, Spain, Germany, Switzerland, Austria, Ireland, Brazil, Korea, Thailand, Hong Kong, Singapore and Indonesia will see the Starbucks ad the first five times that they log in to Facebook.