The last time Air's Jean-Benoit Dunckel and Nicolas Godin played the Shepherd's Bush Empire it was on the back of Moon Safari, an album that surpassed the heights of chill out production.
Producing genuinely organic music, they played bass lines that nestled into the song, rather than being sampled and stuck onto the mix, and delivered keyboard melodies that breathed colour and vitality into our otherwise grey lives. Their sound was as fresh as mountain wind, while somehow being instantly familiar.
The production values of Moon Safari were so robust that replicating the spine tingling sensitivity live seemed an impossible demand.
Amazingly, when they took the stage, the live show was every bit as provocative and sensual as the album. But then something, somewhere, suddenly snapped.
Mid-set the kings of cool sophistication rocked-out and disappeared on a soft-rock, Seventies French festival band trip.
The dance press, who had championed the duo, reacted in righteous indignation.
In fact, although Moon Safari was about production, Air as a band have influences and aspirations that reach well beyond the limitations the French dance music explosion that spawned their success.
Air's second album proper, 10,000 HZ Legend, reveals an array of influences from Kraftwerk to 10CC, Pink Floyd and Super Tramp although thankfully their soft rock 'irony' is far less stated than their compatriots Phoenix.
The difference between the old and the new Air is profound, to say the least.
Tonight the invited upstairs audience is rammed with d-list celebrities, soap opera stars, music industry types and rock stars epitomised in Noel Gallagher and Michael Stipe. Being well connected most of these will have at least heard some of the new album and will know what to expect.
The downstairs audience, some of whom paid touts £100 per ticket, is about to get an alarming wake up call.
Air's stage show is dramatically different. Whereas they appeared in white astronaut outfits for Moon Safari, this time they and the three backing band members (plucked from Beck's band) take to the stage dramatically dressed in black.
Breezy lighting has been rejected for a stage that's at times shrouded in shadow and at other times explodes into a mini Jean-Michel Jarre rock circus.
Apart from these bursts of light, the message is clear. The Moon Safari has moved onto the dark side.
The set opens with the strident intro to the new album, 'Electronic Performers' - a punch bag of electro rock topped off with Godin's computer modified vocals.
Those that haven't heard 10,000 HZ are predictably dumb struck, their expressions breaking into puzzled incomprehension. Expectant smiles freeze into masks concealing disbelief.
To those of us that have heard the album, the replication of the studio sound is again technically perfect as they glide into the second track from the album. The psychedelic, slow-pop of 'How Does It Make You Feel' lightens the dark mood that has enveloped the Empire.
The next song continues to follow the album track list, as Dunckle takes over the lead for the first single, 'Radio # 1'. He delivers the vocals from behind the synth bank, wearing a camp gothic vampire cloak that, apart from being plain weird, heightens the already obvious glam references of the song.
Whereas Daft Punk's latest set draws 'inspiration' from Eighties pop sensation Buggles, Air have forged deeper and settled on something between T-Rex and Bobby Pickett and the Crypt-Kickers.
While still technically perfect, the live performance is marred as a void seems to open up between the Dunckel and Godin, so that the band feels less like a duo plus backing band, than a soloist, Dunckel, and his session musicians. While he rocks out in a Marc Bolan meets Gary Numan fashion, Godin is left holding a guitar on the far corner of the stage. Communication between the two is non-existent.
By now the confusion in the audience has become tangible enough for Jean Benoit to thank the audience for listening to new songs before launching into 'Radian', the most 'old' Air sounding of the new material. This marks the lead into the album's most accessible passage and it turns out to be a gig high point as the duo seem to relax.
Nicolas ditches his guitar to inject some of the old keyboard magic into the Air sound, and the band dumps the album order for the first time to play 'People In The City', another one of the new set's ambient moments.
Having paid homage to their earlier sound, the next track completes the deed by leaping back to 'J'ai Dormi Sous L'eau', before reverting to a sequence from the album's high points in 'Lucky & Unhappy' and 'Sex Born Poison'. This completed they leave the stage with a sudden and unceremonious: "Thank you very much".
The band returns with Godin playing the opening sequence to Moon Safari's 'Talisman', inspiring the warmest applause of the evening to date. This develops into a comparative old school binge, as the band moves onto Virgin Suicides' 'Playground Love' before chucking in the oddly chosen up tempo 'Don't Be Light'.
After a brief break the gentle, rocking bass line of 'La Femme D'Argent' emerges to unite the audience for the last track in unrepentant, rediscovered Moon Safari adulation.
And here's the problem. Moon Safari undoubtedly outshone any other record in its genre. Acts, such as Zero 7, may pick up where the duo left off, but no one can replicate Air's magnificent debut.
Not even Air.
One keyboard line, plucked from the intro track to their first album, outshone every other entire song that was offered this evening.
It's a huge promise to live up to and perhaps wisely Air have chosen to follow it with something completely different.
The trouble is most of us still want Moon Safari.
