Almost too good to be true, Costello continues to defy every expectation, leap tall buildings in a single bound and set imperative new standards of excellence with virtually every further twist of his profoundly energetic imagination.
While much of Imperial Bedroom still sounds to these ears rather more artful than heartfelt, it commanding sweep and urgent deployment of the often abused vocabulary of pop music is emphatic evidence of its author's determination to test the very limit of his talent.
While most of the competition flounders and poses, Costello insists on pushing ahead, continues to provoke, alarm and move his audience with an articulate passion that's simply not matched by anyone else on any other front.
And if any further proof of the sheerly formidable scale of the repertoire that Costello has amassed in five years since My Aim Is True first alerted the nation to the coruscating, often uncomfortable truths of his vision, this concert was definitely it.
Believe me, the epic range of this performance was genuinely staggering. On stage for fully two hours, Elvis and the Attractions cartwheeled through 40 songs (17 of them encores) that spanned his entire career.
It was almost as if Costello had become jacked-off with people being told how good he is and was here going all out to prove it with a set of such uniquely devastating proportions that afterwards there could be no argument about the legitimacy of his claim to being simply the best.
The group started off at a furious clip with a heated exposition of "Accidents Will Happen" and had hurtled through sizzling versions of "Green Shirt" and "Pidgin English" before anyone had caught their breath. The pace remained relentless: songs were re-shaped, re-organised, re-defined and resurrected with an almost manic aplomb.
A slow, sultry blues was inserted into the main thrust of a compelling "Watching The Detectives"; one of the best ever live versions of "King Horse" was prefaced by a violent rendition of the O'Jays "Backstabbers." "Beyond Belief" was transformed into a barnstorming, psychotic rock 'n' roll avalanche. "Clubland" was despatched with such infuriated rage that it might have been played as an overture to the end of civilisation as some of us knew it.
As old Sweeting observed in his review of Costello's Rainbow show last December, the Attractions' versatility and concentrated empathy with the dazzling variety of moods and atmospheres embraced by Elvis' songs is by now legendary.
One now expects them to accommodate the delicate sincerity of ballads like "Alison" and "Kid About It" in almost the same swift movement with which they thunder into the riotous clout of, say, "Pump It Up," "Radio Radio," "Mystery Dance" or the more tricky negotiations of "New Lace Sleeves" or the new, precise, evocative "Shipbuilders." Yes, one expects it, but you're still stunned with the expertise and dash with which they pull it off.
There was simply too much on offer at Southampton to catalogue all the highlights, all the cutting brilliance of this group's performance.
Let it just be said that by the time Costello left the stage after an overpowering version of "Clowntime Is Over," both the band and the audience was joyfully exhausted.
Inevitably, the promising, often impressive cool pop excursions of the Bluebells was rather overwhelmed by the storm of the Attractions, but they acquitted themselves with dependable honour despite a fractious sound system.
The Bluebells, though, don't need me or anyone else to remind them how good they are. But they probably would like your support and applause.
Go on: see them, buy their records ("Forever Young" will soon be on the racks as a 45), make them famous and rich. They deserve it more than most of today's feeble young contenders.
And make sure you stay for the rest of the evening: rock 'n' roll experiences don't come any more crucial, enjoyable or exciting. Over and out.