The ticket read "Beau Temps‚ Mauvais Temps." Rain or shine. Apropos‚ given Thom Yorke's notoriously gloomy disposition‚ balanced with Radiohead's reputation for visually arresting shows. Perhaps this was my way of thanking the Englishmen for their risky decision to release In Rainbows as a name-your-price digital download. Traveling north to Montreal‚ I was acknowledging both their cachet as live artists and their unprecedented commercial largesse.

By choosing the verdant Parc Jean Drapeau for their stand‚ Yorke and Co. turned a $50 ticket into a general admission adventure. Alive with biospheres and roller coasters‚ the Parc is as much playground as urban green, far more intriguing than the concrete wastelands dotting today's concert landscape. Despite the rain -- which dropped in sheets -- tens of thousands gathered‚ moving rhythmically to the PA's pre-show breakbeats. Bodies stretched across the field and up the hill‚ where panoramic city views enticed.

Brooklyn's Grizzly Bear bore the unenviable task of opening for the very avatars of experimental rock. Unfortunately‚ the quartet's lo-fi guitar and fractured indie sounds failed to appease our sharpened expectations. Absent any kinetic showmanship‚ there was little to hold us rapt. Further upstaging Grizzly Bear were the clearing skies. Only 20 minutes prior‚ I ducked raindrops the size of toads. Now‚ impossibly‚ I was staring at an arcing rainbow of reds and oranges‚ stretching to the heavens like God's great smile. Did Radiohead plan this‚ I wondered?

With the storm at rest‚ giant poles (hanging like dormant tendrils just off stage) began to draw outwards‚ forming a curtain over the band's gear. As darkness unraveled‚ and umbrellas collapsed‚ we stood ready. Synthesized bleeps echoed into the great gallery of fans until‚ suddenly‚ the tight snare work from "15 Step" rang clearly through the night. Thom Yorke's plaintive falsetto cut desperately into the track's cool‚ computer-jazz groove‚ subduing our applause. Then‚ in an instant‚ concert screens on either side of the stage exploded with bright liquid light. Montreal cheered wildly‚ as the staggered poles overhead burst into neon Technicolor‚ announcing the arrival of the spaceship Radiohead.

Hyperbole aside‚ Radiohead's stage show is one of the greatest on Earth, a sensory rave bested only‚ perhaps‚ by the late Pink Floyd. Innovative lighting designer Andi Watson abandoned incandescent bulbs for an all-LED rig (the first of its kind)‚ and the effects were mesmerizing. Rainbows of light dripped down the 20-30 foot Versa tubes‚ like fiber optic popsicles‚ while disco chandeliers painted psychedelic daisies in the background.

Impressive as this was‚ I was simply stunned by the sound. Seldom have I heard such a flawless mix. Colin Greenwood's bass moved seductively behind the twin guitars of (brother) Jonny Greenwood and Ed O'Brien‚ while Phil Selway's crisp drum work seemed to sparkle. Richly balanced and feedback-free‚ it was as though the engineers had piped a recording of In Rainbows through two stacks of cathedral-sized speakers.

Bereft of older‚ more thunderous tracks‚ the intimate set was culled predominantly from In Rainbows. And despite a buzzing crowd of 35‚000 the Parc fell silent on every breathless piece. Yorke paused‚ once‚ to lament the dreary weather. "It follows us around‚" he quipped before kicking into "There‚ There." In the distance‚ Montreal's Place Ville-Marie shined its famous beacon as if choreographed to join the spectacle.

A brilliantly executed "All I Need" found Jonny Greenwood scraping chords in sublimely angular movements that sounded like tumbling piano keys. "Nude" and "Reckoner" were haunting‚ understated compositions‚ while the complex harmonies of "Weird Fishes" convinced me there's more voice to this band than its reclusive‚ elfish frontman's. Still‚ Yorke was in three places at once. He'd step into the piano for "Spinning Plates‚" dance impishly on "The Gloaming" and later join Selway on a second kit for the raucous "Bangers and Mash."

Fuzzed guitar favorites like Kid A's "National Anthem" and "Idioteque" brought the house down‚ spurring nearby amusement park La Ronde to deliver its own surprise: A 30-minute fireworks bonanza‚ just over the hill. The band looked on‚ closing with renewed zeal‚ as they blasted "Bodysnatchers" in an audio volley against La Ronde's concussive light show.

Encores ran from captivating ballads ("House of Cards")‚ to monster sing-a-longs ("Karma Police") and schizophrenic anthems ("Paranoid Android"). During a gorgeous rendition of "Faust Arp" Yorke -- distracted by the pyrotechnics over at La Ronde -- actually missed his lines. Bemused‚ he smirked and exclaimed: "Really‚ darling‚ we paid all this money for fireworks; you could at least wait until the end!" The band finished with their spooky epic "Everything in Its Right Place‚" and just as the show started‚ machined beats would close it out. Shrouded in ghostly light‚ each member disappeared‚ while sequencers continued to spit digital noise into the night. The sky was cloudless‚ the fans exhausted. High and dry‚ we'd found the end of the rainbow.