Unlike those dedicated individuals who have seen Phantom 50 or 100 times and Les Mis perhaps even more, I am not a repeated attender of stage musicals.

Yet I have seen – and loved – John Kander and Fred Ebb’s Chicago on at least half a dozen occasions in the 15 years or so of its huge box office success. Amazingly, reception was lukewarm on its first appearance on Broadway in 1975 and its classic status was only recognised after a revival two decades later. Could it be that it was just too good for ‘the decade that taste forgot’?

The last performance I attended before this week was in Oxford last May and featured surprising casting in the person of Jimmy Osmond as the shyster showbiz lawyer Billy Flynn. ‘Surprising’ because Flynn is one mighty bad man and Jimmy is . . . well, an Osmond, famed for the squeaky cleanness of the family’s stage act and in the case of the youngest brother for the nauseating pop hit Long Haired Lover from Liverpool, a defining moment of horror in the aforementioned decade.

While Jimmy sang very well at the New Theatre, his portrayal of Billy was not a patch on the one supplied at Milton Keynes this week by Marti Pellow, the lead singer of chart-topping band Wet Wet Wet. His performance represents a return to the role that supplied him with a career-changing opportunity. Invited by the American producers of the show to take on the part, he went on to triumph in the West End, on Broadway and later in Japan.

He shows us in Billy a shamelessly slippery manipulator – an expert at saving his clients on murder raps and thereby garnering publicity helpful in their stage careers –– who if at work now, rather than in 1920s Chicago, would be an ideal manager of the message for political parties tussling for power at the forthcoming General Election. That he can sing marvellously, as shown on the show-stopping Razzle Dazzle, reveals an aspect of Billy’s talents not shared by any of our present spin doctors, not that I have heard, nor would I wish to, Peter Mandelson in full voice in the bath.

Mention of a leading politico reminds me of the slightly unsettling resemblance between Emma Barton, who plays the feisty killer Roxie Hart this week (as she did in Oxford), and Harriet Harman.

This is a matter, I hasten to add, chiefly of facial features and hairstyle, and not of Ms Harman’s skills as a high-kicking hoofer or – if I dare to mention it – of the ‘escape’, as some saw it, achieved for her by another smart lawyer in a recent highly publicised court case. Also reprising her Oxford role, brilliantly, is Twinny-Lee Moore, who plays Velma Kelly, another showbiz wannabee with a penchant for manslaughter. Her opening All That Jazz reveals at once the fabulous physiques (girls as well as boys) of the chorus dancing with her and the skills of the band (musical director Garth Hall) gleefully swinging behind her. Her closing duet with Roxie, Hot Honey Rag, is no less than a triumph.

It was good to savour again, too, the work of Adam Stafford as Roxie’s much-put -upon dull dog husband – his Mister Cellophane properly touched all hearts – and Wendy Lee Purdy as Matron ‘Mama’ Morton, tough-nut Mrs Fixit (though I’m sure she’d prefer Ms) of Chicago’s correctional institution for miscreant females.

Until Saturday. Box office: 0844 871 7652 (www.ambassador tickets.com/miltonkeynes).