“Answer the call”, urged the banners either side of the stage at the London leg of Live Earth. And, sure enough, many bands rose to the challenge, selflessly trawling their back catalogues for songs that sounded like they might have been written about the environment.

Clearly delighted that his band had a track called Planet Earth, Duran Duran’s Simon Le Bon yelled: “Hands up who didn’t come here on a private jet?” We thought that he was asking us, but it turns out that he was congratulating himself.

No less eager to conform with the mood of eco-conscious, back-catalogue revisionism were Genesis. In Land of Confusion, a furious-looking London cabbie who, on closer inspection, was Phil Collins, sang: “Superman, where are you now?” Was it anger at the disappearing rainforests or the lukewarm reception for their previous song, the 1982 instrumental Duke? Hard to tell, but if Phil didn’t have to catch a plane to Manchester, he would have realised an, um, inconvenient truth that permeated many of the afternoon’s highlights – which was that, actually, some of pop’s finest singalong moments don’t actually do much to promote environmental awareness.

Strumming their acoustic guitars, Damien Rice and David Gray delivered a wonderful Que Sera Sera. It was probably intended ironically, which was more than could be said for the plea issued by Kasabian’s Tom Meighan: “Let’s try and save the polar bears!” Were the polar bears in trouble, specifically? We weren’t sure, but as if to atone for the damn-the-consequences sentiments of a marvellously menacing Empire, a message flashed up urging us to recycle.

You get the sense that Red Hot Chili Peppers are a band who recycle (and not just old Funkadelic riffs).

This funky eight-legged monument to sustained spirulina consumption elicited front-to-back cheering. After they closed with a riotous By the Way, hundreds left altogether, confident that there was nothing left for them here. Bloc Party’s earnest, undergrad bleatings did little to disavow them of the notion. Spinal Tap reformed seemingly to prove that even good jokes stop being funny after a while.

Spinal Tap notwithstanding, the harder they rocked the better they fared. Metallica seized the opportunity to reposition themselves as the mainstream metal band of choice with a compressed set of old favourites. The Beastie Boys kangarooed about the stage in suits and shades but only really triumphed when they donned instruments for a grungy Sabotage. By the time his band were due on, Foo Fighters’ Dave Grohl must have known that the air-punching anthems in which his group specialise would meet with unanimous adoration. Singing himself hoarse on Times Like These, the hirsute singer joked that their next Wembley gig would be a headlining one. He may be right.

For many of those fans it ended here. Terence Stamp came on and “symbolically” turned off as many lights as health and safety would allow. They remained off for a time which, handily, meant that Madonna couldn’t see the hundreds of empty seats that greeted her drippy new eco-dirge Hey You. She pulled it back magnificently, though, by summoning Eugene Hutz and Sergei Ryabtsev from Gogol Bordello to give La Isla Bonita a gypsy-punk makeover. Flanked by her default gang of male dancers (and an amusingly exhausted Hutz), Hung up was thrilling enough to almost make you forget about the frequently underwhelming eight hours of music that had preceded it.

Indeed, on a day when Paolo Nutini got a bigger cheer than Al Gore, you had to wonder about the efficacy of events like this. The indifference that met all the awareness-raising films couldn’t have been in more marked contrast to the atmosphere here at Live Aid 22 years previously – when the medium and the message seemed entwined in people’s minds. Next time they’d be better off simulating the conditions of a huge landfill and locking everyone in for the day while Madonna, Metallica, Foo Fighters et al attempt to distract us from the stench. Because this idea that good behaviour can be mollycoddled out of audiences by pop music is beginning to seem a little quaint.

Costing the Earth

— More than 100 acts performed in 24 hours in London, Sydney, Tokyo, Shanghai, Hamburg, Johannesburg, Rio de Janeiro and New Jersey

—The concerts were broadcast on 120 television networks around the world

— Cost of standard ticket for Wembley concert: £55 Green measures at the venues included: recycled towels and toilet paper, biodegradable soaps and earth-friendly cleaning products, ceiling fans in place of air-conditioning

— Proceeds given to: Alliance for Climate Protection and other international nongovernmental organisations

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