The site, which grew in popularity thanks to its early adoption by emerging bands and their fans, has in recent months taken a more active role in promoting social causes, such as environmental awareness and voter registration.

“The crisis in Darfur is a global concern and as a global community we have a responsibility to take action,” Chris DeWolfe, MySpace’s chief executive, said in a statement. “MySpace’s reach gives us an extraordinary opportunity to spread the word and empower individuals to help address the horrors in Darfur.”

Some 2.5 million people have been made homeless by three years of fighting between the Sudanese government and rebel groups in the vast, arid Darfur region of western Sudan. At least another 200,000 people have been killed since hostilities erupted.

Just last week, U.N. Secretary-General Kofi Annan warned that Darfur is creeping ever closer to catastrophe, with rape and violence on the rise and humanitarian access at its lowest level since 2004.

The concerts will take place October 21. Artists include TV on the Radio in Philadelphia, Alice in Chains in Winston-Salem, North Carolina, Ziggy Marley in Medford, Oregon, Citizen Cope in Seattle, Gov’t Mule in Spokane, Washington, and Insane Clown Posse in St. Petersburg, Florida.

Other concerts will take place in Sacramento, San Diego and San Francisco, California; Melbourne, Florida; Atlanta; Louisville, Kentucky; St. Paul, Minnesota; Reno, Nevada; Baltimore; Asheville, North Carolina; Charleston, South Carolina; Milwaukee; and Washington, D.C.

A Canadian show will take place in Toronto.

Bands – pop, rock, country and reggae, among others – agreed to donate part of their ticket proceeds to Oxfam’s relief efforts in Sudan and neighboring Chad.

The campaign also includes a public service announcement featuring Samuel L. Jackson. Besides MySpace, it will appear on television and in movie theaters before films released by 20th Century Fox, which like MySpace is owned by News Corp.