About 20 acts will each record a new song in a single day on the 10th anniversary of the first War Child album, Help, which raised nearly £2m for children in Bosnia.
The new album, Help: A Day in the Life, (and individual tracks) will be available for downloading on the War Child website and elsewhere online on the day of recording on 9 September, making it the fastest album ever made. A CD will be released in the following weeks.
Radiohead, whose track "Lucky" was one of the highlights of the first CD, were among the first bands to sign up to the new venture.
Other acts expected to take part include the Zutons, Bloc Party, Hard-Fi, Elbow and Manic Street Preachers, who also took part in the original project by recording Burt Bacharach's "Raindrops Keep Falling on My Head".
Despite fears that charity fatigue may have set in after recent fundraising for tsunami victims and Live8, the charity War Child hopes the new album will benefit children in Iraq, Afghanistan, Bosnia and the Democratic Republic of Congo.
Mark Waddington, War Child's chief executive officer, said: "As a music fan, I know what the original Help album meant and as the present CEO of War Child I know what it achieved.
"It was my intention that any new album should match up to the feats of the past. That's why we have set ourselves the challenge of remaking history and releasing the fastest album ever, again. It's a tall order but we feel with the support of amazing artists such as Radiohead and Hard-Fi, we can make it happen."
The original Help was the brainchild of four music industry publicists, Terri Hall, Tony Crean, Rob Partridge and Anton Brookes who had been shocked by the massacre at Srebrenica and the sieges of Sarajevo and Mostar.
It was recorded in studios across Europe on 4 September 1995, by artists including Orbital, Stone Roses, Suede, Massive Attack, P J Harvey and Sinead O'Connor with Brian Eno as its executive producer. Paul McCartney recorded a version of "Come Together" with Paul Weller and Noel Gallagher of Oasis.
The finished product was released less than a week later and went straight into the charts at number one after selling more than 71,000 copies on its first day - just six days after recording began. It raised enough money to enable War Child to carry out aid projects in Bosnia Herzegovina.
War Child had been established two years earlier specifically in response to the conflict in the Balkans.