In October, gigs in the 30 capsules of the London Eye were billed as "the world's first music festival in the sky". The cream of London's urban talent, including Ms Dynamite, dubstep artists Skream and Benga, Wretch 32, Kano and Goldie, Andrew Weatherall, Bestival curator Rob da Bank, and Hot Chip's Joe Goddard each performed one-off shows on the 135-metre-high wheel as it turned. Fans not only enjoyed an unusually intimate hour-long performance (each pod takes 27), but had the view of London's skyline as a backdrop. Moving the equipment into the pods was the organisers' biggest obstacle, especially as the Eye was in continuous motion.
"Logistically, it was one of the more complicated events we've staged", says Torsten Schmidt, co-founder of Red Bull Music Academy and organiser of the event.
"Once the Eye was empty, it took one revolution to load everything and set up, another with the artists on board to soundcheck, then two full revolutions with the fans inside. And remember the Eye doesn't stop so we had to work at pace." Each pod was limited to the 27 people including sound engineer, security, artists, audience and mini-bar, so space was tight, with some more squeezed than others as the set-ups varied from DJ booth to live bands and, in one case, a string quartet. Those who didn't make it into a capsule could tune in online to hear any of the gigs streamed live.
It didn't help that performer Skream, one half of Magnetic Man, suffers from vertigo. "If only I'd have known," he said. "I hate heights."
In November, 3,000 people gathered along the Thames to watch rising electronic act Totally Enormous Extinct Dinosaurs and superstar producer Deadmau5 perform against a backdrop of the 118-metre-high Millbank Tower. Deadmau5, positioned on the rooftop of the building's fourth storey, tiny in his DJ enclave and shrouded by pink light, was projected live – not on the typical screens you find at vast concerts – but onto the skyscraper itself, along with a light show by leading 4D-projection artists, transforming Millbank Tower.
Such was the effort and cost in making it (rumoured to be £2m), the show could only have been sponsored by a big brand – Nokia, which was launching its latest handset. All 800 windows making up the building needed to be covered in vinyl, taking nine days to put up and take down, and it took five days to manoeuvre all the equipment onto the four storey-high stage, with a team of two brave men lowered up and down the building in a cradle. It made for a spectacular setting, drawing the audience's gaze towards the sky as they listened to the pounding beats of the cutting-edge DJ. The biggest issues with gigs in high places, says the project director at Mission, JD O'Lone, are health and safety: "One of the issues, especially on a roof, is the wind. With this gig we had wind funnelled down the Thames and gusts of anything up to 30 or 40mph. Millbank Tower acts as a sail which catches the wind and can push the wind under any structure. We had to be sure that our stage could handle any wind, which means engineer-plans and structural drawings to make sure we [were] not putting anyone at risk."
When an artist plays from a roof, the sound delay has to be taken into consideration. With a distance of up to 350 metres between the artists and the audience, an audio link was used to ensure everyone could hear the music simultaneously – made all the more complicated by the projection itself being designed to go in time with the Deadmau5 music.
The alpine mountain
Perhaps most ambitious of all are the increasing number of music festivals in the snow, where some gigs are so high in the mountains that they can be accessed by cable-car only. Snowbombing, which in its 13th year has Snoop Dogg, DJ Shadow and The Vaccines on the bill, features a 300-capacity Arctic Disco that is situated on an Alpine plateau 2,000 metres high, in the quaint Austrian village of Mayrhofen.
It doesn't just pose a safety issue for the gig-goers – who are given a safety briefing about the effects of alcohol at altitude and in icy conditions before they reach the venue. The altitude also poses practical dilemmas for the organisers. Low temperature makes guitar-playing, in particular noodling solos, very difficult indeed, while strong winds you get at that height means that the proscenium-arch stages that are typically used must be abandoned. Instead, the backdrop is left untethered so it can't trap the wind (which could lead the whole stage to blow away). Last year The Whip performed on the mountain, where others, including Fatboy Slim, Mr Hudson, and Reverend and the Makers have appeared. Another venue is within the Floitental valley, better known as The Forgotten Valley, so-called for its steep sides and avalanche risk. "We always check with the Avalanche Commission prior to taking people up there", assure the organisers.
Jamiroquai broke records for the fastest and highest performance of a concert aboard a private Boeing 757, in February 2007. Launching their compilation album High Times: Singles 1992-2006, Jay Kay and his band performed a greatest-hits set 35,000 feet in the sky to competition winners as they travelled from Munich to Athens. The gig was organised and promoted by Sony Ericsson. Kay said: "No one has done a gig like this before. Rock'n'roll is all about pushing the boundaries and Gig in the Sky certainly does that." It broke world records as the highest gig, only to be trumped by James Blunt who repeated the feat on a private jet in June last year, at an altitude of 41,000 feet, in a concert organised by Heart FM.
Following the Beatles' famous gig on top of the Apple building in 1969, Bon Jovi made headlines when they kicked off their 12-date residency with a gig from the rooftop of London's O2 Arena, in June 2010. They became the first act to perform on top of the building, and the show was beamed live onto the high-definition screen in front of the Arena. The height of the roof, which at 58 metres stands as high above the ground as Nelson's Column, meant the musicians needed help from mountaineers to reach the top.
The Scots peak
Essex band Kings Cross gained themselves some publicity when they played the summit of Ben Nevis. The band took their instruments and PA system to the top of the Scottish peak, the highest in the UK, to raise money for charity. They played to around 200 climbers. The band's Peter Vicary said: "It was not a lot different, except being freezing cold. We could only do about four songs before my fingers started freezing and I actually couldn't feel them for a couple of the songs." Other British musicians had climbed higher, playing the highest non-flying gig, above Mount Everest's Base Camp, at 5,545 metres, at Kalar Pattar, in Tibet, back in 2005. The artists, from five different bands, performed a 40-minute concert to 100 mountaineers.
Snowbombing runs from 9 to 14 April (www.snowbombing.com)