It’s surely been a while since Sparks had anything to prove, but exactly 10 years ago they were putting themselves to the test anyway. Sparks Spectacular: 21 Albums in 21 Nights – three solid weeks playing an entirely different show every night – was an unprecedented take on the trend for playing classic records in their entirety. It’s hard to imagine any other band of similar vintage attempting this colossal endeavour. The exercise demonstrated to the public, and to the band too perhaps, the strength and depth of all of their material across the years. Even their cruelly ignored albums are blessed with sparkling moments of inimitable genius.

A long time passed before last year’s brilliantly received Hippopotamus, and the tour rolls into town again thanks to the unexpected success of this album number 22. In 2017 they scored their first top 10 album in the UK since 1974, and if we’re in the business of looking backwards then this tour also marks Sparks’ 50th anniversary as a band - not that you’d know it. While the Rolling Stones milked their half century with a tour proclaiming their longevity, the band who started life as Halfnelson in 1968 are steadfastly ignoring their golden anniversary. In Sparks’ world, such numbers are an irrelevance. When I asked Ron and Russell last year if they would be organising a knees-up in celebration of five decades of rock & roll service, Ron looked horrified: “If there are [celebrations] then they’ll have to be thrown by other people. It’s something we would rather avoid.”

As if to accentuate the purple patch they’re currently enjoying, the band are all dressed in fetching off-pink tonight, with Russell particularly resplendent in an elegant, rosy coat. Sparks have experienced unexpected hotspots at peculiar times in far away places throughout their career. Glam rock stardom in Britain in the mid 70s; disco celebrities in France in the late 70s and early 80s; indie cred back in the States during the early to mid 80s; chart botherers in Germany in the mid 90s and so on. During the 21st century they’ve picked up diverse followings from within the hip hop community and the avant garde, with cineastes and genuine pop fans from yet another generation just discovering their work for the first time.

They may now have their best drilled band too. The a cappella beginnings that lead into the ostentatious, rambunctious intro to ‘At Work, At Home, At Play’ from Propaganda exemplifies a group in finest fettle, and ‘Hasta Mañana, Monsieur’ from Kimono My House is as emphatic as you would hope for. They swerve skilfully from glam to disco on ‘Tryouts For The Human Race’ and later ‘The Number One Song In Heaven’, recorded with Giorgio Moroder in 1979. Then there’s the harder-to-pin-down neoclassicism of Lil Beethoven on songs like ‘My Baby’s Taking Me Home’ and ‘Suburban Homeboy’ from 2002. With Sparks, sometimes it takes time for the penny to drop, and I kick myself when it suddenly occurs to me for the first time that ‘The Rhythm Thief’ has no drumming on it - a fastidious detail that’s obscured by the vehemence of the groove. (Speaking of no drummer, Sparks have been through plenty of percussionists and other musicians since the days of Norman ‘Dinky’ Diamond - in fact they’ve had nearly as many lineup changes over the years as The Fall, though they’ve been less publicised, perhaps because Ron and Russell are not demonstrably despotic.)

As for getting on a bit, their message seems to be clear: ‘Je ne regrette rien’. And, maybe, ‘On y va’. Hippopotamus is full of joie de vivre and surreal sketches, from the title track to music hall numbers about hanging out with someone who’s perfect aside from being a joy vacuum (‘I Wish You Were Fun’); via songs that celebrate the joys of the ‘Missionary Position’ and nothing else (“You might pride yourself, you’re so avant garde / But we're neoclassicists, I guess at heart”). They’re all played with aplomb tonight alongside songs that still sound great 45 years later. They may have been at it for 50 years but what they’re doing right now is the most important thing.

And if they’re far from ready to face the final curtain, Russell does at least get to sing the famous Frank Sinatra song written by Claude Francois - or a few bars of it at least - ahead of ‘When Do I Get To Sing “My Way”?’. You can do whatever you like when you’ve nothing left to prove.