Chris Martin, Lily Allen and Alesha Dixon are among celebrities urging volunteers to become "dementia friends" and help care for those with the degenerative condition.
Volunteers who take part in the scheme will be able to attend free sessions to learn how to spot the signs of dementia and offer support for sufferers, the Alzheimer's Society said.
In a new ad which will be aired for the first time tonight, the pop stars will be seen performing The Beatles' track I Get By With A Little Help From My Friends.
Other celebrities involved in the ad include comedian Simon Pegg, actor Ray Winstone, footballer Leighton Baines and presenter Paul O'Grady.
More top news
Man City tightened their grasp on fourth spot with a comfortable 2-0 victory over West Ham at the Etihad Stadium
The Labour leader has a certain swagger in this election campaign and his team are upbeat. But why?
Police are appealing for help in tracing a family of six who are feared to be travelling to Syria.