There have been a myriad Elvis Costellos over the years: vitriolic, smug, ahead of the times, behind the times, quixotic and even simplistic. 2003's version is perhaps the most unlikely yet: a vulnerable puppy of love.
This latest persona is inspired by his relationship with Canadian jazz chanteuse Diana Krall (present on Saturday, accompanied by American actor Clint Eastwood), which informs the second half of his new album, North.
Having introduced the North sections as "exceedingly quiet", Costello sang the bulk of them without his usual prop of a guitar. Accompanied for the most part by the piano of Attraction Steve Nieve (who, judging by his appearance, is sleeping rough these days), briefly by The Brodsky Quartet, but occasionally wholly solo (at the very death without vocal amplification), Costello shared his joy.
Indeed, as he played piano on the self-deprecating "Let Me Tell You About Her" like a gifted Richard Stillgoe, he displayed a hitherto unheralded sense of comic timing.
Over the course of two-and-a-quarter hours - the encores were longer than the actual set - there was ample room for old as well as new. The spartan format and Nieve's adaptability meant anything was possible, even a cover of Smokey Robinson's lovelorn "You've Really Got A Hold On Me" halfway through the bile-encrusted "Dark, Deep Truthful Mirror."
Encouragingly, the more recent material, such as "45," is ageing well, suggesting Costello's gifts have been taken for granted of late.
The old Costellos lurked in the background. A politicised section included the riproaring "(What's So Funny 'Bout) Peace Love And Understanding?" and "Shipbuilding," which still seethes with stoic dignity. The Brodsky Quartet provided a sinister backdrop to the already malevolent "Pills And Soap" and a gorgeous setting for "You Left Me In The Dark," from North's first half, which details the disintegration of his marriage to Cait O'Riordan. Tellingly, this remained unsaid.
It's tricky to see where Costello can go from here, but predicting his next move has always been futile. Let's just hope he's sufficiently canny to resist the temptation of a duets album with Krall.