Hundreds of thousands of spectators fill the Benjamin Franklin Parkway to watch the Live 8 concert in Philadelphia

Some of the biggest names in popular music performed in concerts across the globe Saturday to raise awareness about the plight of the poor in Africa. The Live 8 concert series was timed to draw the attention of leaders of the G8 - the world's wealthiest nations - who will be meeting in Scotland next week.

The former Beatle, Sir Paul McCartney, backed by the Irish rock band, U2, kicked off the London Live 8 concert Saturday with a rousing version of the Beatle's hit, Sergeant Pepper's Lonely Hearts Club Band. The London concert was one of 10 concerts taking place Saturday.

"I just think the opening is one of the great rock-and-roll moments of all time, I really do think that," said Bob Geldof, the Live 8 organizer, who organized a similar concert for Africa 20 years ago, called Live Aid.

Paul McCartney, center, and members of U2, perform at Live 8 concert in Hyde Park, London, Saturday

Mr. Geldof said he decided to organize this year's event to coincide with next week's summit in Scotland of the seven leading industrialized countries and Russia, to pressure the world's most powerful leaders to alleviate African poverty. Concerts were staged Saturday in each of the eight countries and South Africa.

U.N. Secretary-General Kofi Annan appeared on stage in London to thank those in attendance and the three billion people organizers said were watching on television and the Internet around the world.

"This is really the United Nations," he said. "The whole world has come together in solidarity with the poor. On behalf of the poor, the voiceless and the weak, I say, thank you."

Also in London was Microsoft founder and chairman Bill Gates, whose foundation has spent millions of dollars on helping to solve public health issues in Africa.

"Well, if the resources are given by the rich countries, lives can be saved," he said. "We know how to spend those resources in a wise way, and I think it's important for people to understand that, and to know that this kind of grassroots support really makes a difference."

British Prime Minister Tony Blair, who chairs the G8 this year, has made development in Africa a priority for next week's summit. However, his proposal that rich nations double the amount of aid they give to Africa was initially received coolly by the Bush administration. But late last week, Mr. Bush announced a plan to spend $1.2 billion to cut malaria deaths in half by 2010 in Africa. The president also said he supports total debt relief for 14 of Africa's poorest nations with another 18 under consideration.

In South Africa, site of the only Live 8 concert on the continent, Anglican archbishop and Nobel laureate Desmond Tutu welcomed the debt cancellation by the G8 countries.

"Let them have a chance to change things significantly for the poor. They started well with canceling $40 billion of debt. Now, let them continue in that direction and change the trade laws," he said.

In Philadelphia, where the U.S. concert was held, Bob Marley's widow, Rita, and their son, Steven, joined an American hip-hop group, The Black Eyed Peas, for a spirited cover of  Get Up, Stand Up.