A 24-hour music extravaganza stretching from Sydney, Australia, to New Jersey wrapped up Saturday at Giants Stadium with a performance by the newly reunited Police after a series of concerts spanning seven continents and showcasing more than 100 musical acts.

The concerts, with shows in London, Sydney, Tokyo, Kyoto, Shanghai, Hamburg, Johannesburg, Rio de Janeiro, were designed to raise awareness about global warming. Organizers described it as the biggest musical event ever staged, even larger than Live 8 or Live Aid.

The events were inspired and backed by Al Gore, who has made educating the world about global warming his main priority since leaving politics after his losing presidential run. Gore appeared at a number of the events – in one form or another.

In Sydney, he talked to the crowd by video. In Tokyo he appeared in a hologram. And in New Jersey, the former vice president took the stage in person.

Gore called on fans to adhere to a seven-point pledge to tackle global warming including demanding more renewable energy and helping to preserve forests.

“Put all of this energy in your heart and help us solve the climate crisis,” said the former vice president, appearing on stage at the end of the New Jersey concert with his wife Tipper.

The theme at many of the concerts seemed to be that fighting global warming was not about sacrifice as much as it was about making little changes such as buying low-energy light bulbs or unplugging electrical outlets when they are not in use.

The musical acts were interspersed with speakers such as actress Cameron Diaz who said the concert was not about “gloom and doom” and primatologist Jane Goodall who greeted the crowd with an imitation chimpanzee cry.

Many at the New Jersey show seemed to focus mostly on the music.

The Police were joined by Kanye West and John Mayer for a rendition of “Message in a Bottle” to wrap up the concert. Except for a few words interspersed into an improvised rap section of the song, they stayed away from making any messages.

Hometown rockers Bon Jovi were introduced by Gore who said they were one of the first acts to volunteer when the concerts were announced. The closest that frontman Jon Bon Jovi got to making a statement was calling on fans to “Let them know what New Jersey is all about.” The Giants Stadium show had been billed by concert organizers as a New York event even though it took place in New Jersey.

Rocker Melissa Etheridge pounded out her song “I Need to Wake Up,” which was featured in Gore’s documentary “An Inconvenient Truth” and won an Oscar for best song earlier this year.

At the London show, the stadium’s nonessential lights were turned off before the closing act – Madonna – came on stage, leaving the concert dark except for the glow of exit lights and the flashes of cameras.

“Let’s hope the concerts that are happening around the world are not just about entertainment, but about starting a revolution,” said Madonna, who sang a song she wrote for Live Earth called “Hey You.”

The Beastie Boys wore their feelings on their sleeves, performing a furious set of their hits in tailored green suits and shades when they took the stage at Wembley Stadium.

Besides The Police, the concerts also featured a reunited Genesis and the Smashing Pumpkins.

The concerts were billed as environmentally friendly with recycling containers dispersed around the stadium, generators running on biofuels and a stage made of recycled tires.

But that did not stop criticism of the event from many who asked why rock stars – with their jet-setting, high-consumption lifestyles – should be asking others to be more environmentally friendly. Others questioned how a concert without a clear-cut goal such as raising money could be effective.

Many of the musicians acknowledged that they were not rock stars when it came to the environment, but said it was important to start a discussion about climate change.

“If you want to peg me as not being entirely eco-friendly, you’ll win,” said John Mayer, speaking to reporters after his set. “We’re just getting together saying ‘We want to be healthier.'”

Rocker Dave Matthews said he tries to go green by driving a hybrid vehicle that uses less gasoline than other vehicles and uses cloth diapers for his new baby.

But Matthews admitted he wasn’t perfect.

“I’m flawed. Cows fart and so do I,” he said, referring to methane gas released by cows that also contributes to global warming.

At other venues around the globe, aboriginal dancers opened the first concert in Sydney, Latin artist Shakira shook her hips in front of a crowd at Hamburg, and Linkin Park entertained fans at a Tokyo concert.

On Rio’s Copacabana Beach, about 400,000 people gathered as the sun set to hear Lenny Kravitz, Macy Gray, Pharrell Williams and Brazilian superstar Jorge Ben Jor. And in Johannesburg, the concert ended with the artists and audience clapping out SOS in morse code – a reference to the evening’s theme of answering the call to save the planet.

At the New Jersey concert, the crowd was dotted with people who heeded the call to wear green. Many said they were already taking steps at home to lead a little more green lifestyle, and felt the concert wasn’t just about music.

“It’s cool that whole continents are meeting up. We’re all tied to one another,” said Katie Juron, 24, of Warwick, N.Y. “Everyone is interconnected.”