Patrick Errington at the We Love Green Festival

Yes, summer is ending. The air is hardening and the green of those warm summer months is already being wrapped up in the Parisian autumn scarves. The leaves are rusting as the city drags itself back to work, to real life.

But last weekend, in the Bois de Boulogne, Parisians had just one more bucolic weekend with performers including Charlotte Gainsbourg, Beirut, Norah Jones and James Blake to hit the snooze button and keep the summer dream alive at the annual We Love Green festival.

Despite the hippie name and ambitions, the festival began not as out-and-out bohemian as I was expecting. Yes, the central manifesto of a low-impact, renewable, recyclable festival was on full display from the first, but, maybe because the temperature dipped as sharply as the sun did, or maybe because it’s Paris and letting one’s pristinely coiffed hair down is quite against stereotype, the event felt somewhat metropolitan.

This was certainly not due to the setup. The space was entirely biodegradable thanks largely to the design of Sébastien Préchoux, who created the huts and teepees entirely of scrap wood and ecological fiber; Amélie Legrand’s artistic touches in the organic sculptures that dotted the scene; and the architectural genius of Jacques Ferrier’s low-impact stage structure. The electrical energy powering the lights and stage effects came, as much as possible, from the arrays of solar panels and wind turbines—the children’s area even had energy-producing games! Tucked away in Paris’s western-most forest, bracketing the city limits, where only the angular caps of La Défense can be seen above the trees, you’d be hard pressed to find a greener festival in Oz’s Emerald City. However, despite the flower crowns and cornucopia of organic eats, the first few performers had to fight hard against that very Parisian reserve.

But then it happened. There came a point in the early evening when something changed. Maybe it was in the angling sun that made the spectator’s shadows stretch toward the stage, maybe it was something in the smell of grass and trees or because the headlining groups hit that perfect chord and the darkness could begin to hide the uncharacteristic frivolity, but suddenly the shoes came off and the hair came down and the party began.

A few groups really stood out. Norah Jones was fittingly beautiful and organic, her voice as warm as a hot tub, but James Blake really stole the show that evening. His technical production was flawless, his vocals so softly powerful, his effect on the audience truly astounding. We were left like snakes, held rapt by the charmer’s tune. Beirut too, following a wildly entertaining performance by Camille that broke everyone free of their urban inhibitions, who in the space of a song could morph from a personal, intimately quiet moment to one of tremendous energy and release.

By the time the nights were building to their final heroic flashes of renewable-energy-powered light, you could see in the faces of the crowd that this place had truly become a dream. Only the swath of white light from the promontory of the Eiffel Tower wiping across the sky could remind us where we really were. And as we walked back through the darkness and sat silently in the métro, it felt like climbing up the wall from sleep. Something in the ephemeral nature of the event, how today the evidence of the experience is decomposing away, makes one wonder if it happened at all. But that’s the best thing about any dream.

The 2012 We Love Green festival ran September 14-16th in the Parc de Bagatelle, Paris.