Jamelia, Fatboy Slim and The Kooks will perform in a specially-converted Oxfam shop in London as part of a festival organised by the charity in October.
Jamelia's hit singles include See it in a Boy's Eyes and Superstar
The stars have signed up for Oxjam, which aims to raise £1 million to help tackle poverty around the world.
Music memorabilia will be sold during the day at the shop - its precise location has not yet been confirmed - and it will host the gigs at night.
The Chemical Brothers and Jarvis Cocker have designed badges for the campaign.
The Kooks will perform an acoustic set on Monday, 1 October, with Cocker also on the bill as a DJ that evening.
Jamelia and Killa Kela have been confirmed for the following day, while Hot Chip and DJ Bobby Friction will appear on Wednesday of that week.
Fatboy Slim - real name Norman Cook - and Emmanuel Jal round off the live sets on Thursday, 4 October.
Cook said he had always donated his unwanted records to Oxfam but performing in one of its charity shops "will be a first", and promised "a few choice tunes".
Cocker has created a badge for the campaign and will play a DJ set
For the Kooks, singer Luke Pritchard praised the campaign, saying it was all about "thousands of small events adding up to something much bigger" to make a difference.
Oxfam said its target of £1 million would fund the provision of drinking water for almost 1.4 million people, or 20,000 emergency shelters, or medicine to treat 10,000 people.
Its month-long festival is expected to involve about 40,000 musicians in 3,000 different events.
These will include a simultaneous 12-hour "buskathon" in about a dozen British cities and a travelling guitar, which will be taken from John O'Groats to Land's End throughout October and will be used at a different Oxjam show each day.