Robbie Williams, Roundhouse, London<br/>Spandau Ballet, O2, London

Robbie Williams puts on his first gig in three years, but that's nothing compared with the lucrative rebirth of Spandau Ballet &ndash; minus the kilts

With unsold copies of Rudebox providing compacted ballast for the Olympic Village, the careful calculation behind Robbie Williams's latest comeback is critical. It's always hazardous to write of a consensual "we", but there was a time when "we" broadly liked Robbie Williams. His pop video persona had Britain charmed.

At some indefinable moment, something changed, and the incessant reportage of his boy-cries-wolf traumas became tedious and slightly sad (in the unsympathetic sense); nowadays "who cares?" is the resounding response.

He does, nevertheless, retain a rabid if reduced following, as proven by a few lunatics on lilos camping on Chalk Farm Road overnight, and by holding his first gig in three years in the relatively intimate Roundhouse, with the BBC providing a miniature orchestra to class it up a bit.

If you want to reclaim your status as a pop star, it helps if you look like one. On this score, Williams fails. His face is still that of an eight-year-old cheeky scamp from a TV ad casting agency, but his Clooney-esque poivre-et-sel hair reveals his age, and his dress sense: blue denim and brown shoes, like a dad at a barbecue, and a grey shirt with sweat patches under the arms, like a summertime strap-hanger on the London Underground.

This Electric Proms set, ostensibly a launch for imminent comeback album Reality Killed the Video Star but dotted with crowd-pleasing hits such as "Feel" and "Angels", features personnel including Art of Noise's Anne Dudley on piano, Lol Creme of 10cc and "Godley & ..." on backing vocals and, on bass, Trevor Horn, who produced Reality and whom Williams honours by encoring with a cover of "Video Killed the Radio Star". Twitching and gurning, twirling a Freddie Mercury-style half-length mic stand like a drunken fencer, doing the chimp walk and miming fellatio with a TV camera, he takes the "y" out of "cocky".

The new material is a mixed bag. There's a lost Guy Chambers song built on a terrible "blasphemy"/"blast for me" pun, a soppy number called "I Won't Do That to You" for his "missus" (American soap actress Ayda Field), and the George Michael-ish disco tune "Starstruck" with Goldfrappy Star Trekky backing vocals. He tells us he's pleased the front row isn't singing along, because it proves the album hasn't leaked. Give it three months and see if he's still so happy.

Some of the banter is better than the actual music. Before "No Regrets" (its lyrics altered to make them less anti-Take That), he cheesily tells us "I've got a new best mate and his name's Gary Barlow", and reminisces about meeting up with his former bandmates last year, clearing the air, and getting on so well that he went out and had a TT logo tattooed on his wrist, to which Gary, Jason, Mark and Howard exclaimed "You prick!" in unison. And the anecdote about getting 40,000 people at the Old Trafford cricket ground to point and boo at the VIP section for not standing up and dancing – only to find that it was the disabled section – is immortal.

But "Millennium", with its invitation to "come on and see the sarcasm in my eyes", inadvertently reveals what was always unappealing about Williams, beneath the twinkly-eyed surface: rather than make an emotional connection, Williams has always prioritised chasing the zeitgeist, with layers of protective irony. The danger of that is that when the zeitgeist moves on, you're stranded high and dry.

So, a decade since his cultural peak, here he is trying to play catch-up. The single "Bodies" may have stalled at No 2, but it is – as he's at pains to point out – his highest first-week sale since "Rock DJ". Operation Robbie Relaunch is a qualified success.

"From half-spoken shadows emerges a canvas. A kiss of light breaks to reveal a moment when all mirrors are redundant. Listen to the portrait of the dance of perfection: the Spandau Ballet." This pretentious prose-poem is how Robert Elms, to stifled giggles, introduced the then painfully hip Spands at the Scala in 1980. Their 2009 comeback, blatantly driven by accounting rather than art, steers clear of anything so baroque, and, as though embarrassed by it, excises the camp of their kilted early days. Sure, they open with rent-boy confessional "To Cut a Long Story Short", but the homo-eroticism of "Musclebound" – a Top 10 hit – is omitted.

Instead, the Success Coat years (those shoulder-padded frock coats that all Eighties bands wore once they'd made a few quid) are emphasised, which plays well with a crowd composed largely of women who used to be 14 once, and their suffering husbands. Martin Kemp gets the biggest scream, followed by Steve "Plonker" Norman.

There was always something unlovable about Spandau, and a lot of it was to do with Tony Hadley, a wally who clearly never "got" the New Romantic aesthetic. It's Hadley's croon that drives their worst, if most successful material. I'll admit to setting fire to my post-punk principles for a shoutalong to "I'll Fly for You", but not for sax-backed soft rock like the unimaginably patronising "Through the Barricades", whose refrain "And we made our love on wasteland" isn't even Spandau's worst lyric. For that, it's a coin-toss between "She used to be a diplomat/But now she's down the Laundromat" and "These are my salad days/Slowly being eaten away".

It's worth enduring this dross for the good stuff: a killer white funk medley of "Chant No 1/Paint Me Down" and "The Freeze". Maybe it is all about the money, but when you're swishing your kilt to the Spands in full-on synth mode, it barely matters.