This is the double act you never knew wanted. But the partnership between Edinburgh Comedy Award winners John Kearns and Adam Riches makes so much sense, even before you see this formidable tribute – of sorts – to ‘the most successful musical double act nobody you know has ever seen’.

It’s an inspired choice to select stars that their hip comedy audience are vaguely aware of, but don’t really know, allowing them to project any personality they like onto these showbusiness avatars. 

They don’t even really need to be Michael Ball and Alfie Boe, when it comes down to it. That they are provides an extra layer of jokes for this rich comedy lasagne, but at its core, the hour explores the relationship between a longstanding double act and the banality of mainstream entertainment.

Riches’ suave, superficial Ball is the senior partner, and the more cynical one, signing big sponsorship deals and insisting on sticking to their commercially successful cover-versions format.  Meanwhile, Kearns’s Boe has grander artistic visions for a very specifically themed show. With a soft Lancashire accent, he’s obviously grappling with insecurities and frustrations at the complacency of their act. His ambition to perform an original song is a postmodern update on Ernie Wise seeking to do the latest play what he wrote.

Indeed, Riches and Kearns pull off a solid approximation of a Morecambe-and-Wise style double act, a dynamic defined by banter but supportive beneath the surface. Their initial to-and-fro would actually work on a mainstream light ent level, but there’s just enough acknowledgement of the cheesiness to make it knowing. And the comics behind these tuxedoed singers and vintage microphones make each other laugh occasionally, adding a sense of joy and semi-spontaneity.

Indeed, any musings on the nature of their alter-egos’ relationship comes second to revealing in the gleeful fun of performing this just-for-larks side project, directed by Pappy’s member Tom Parry, who’s well-known for his own spirited comic performances. When the duo launch into their second song, everyone internally asks: ‘Are they really going to commit to this?’ The answer is a resounding ‘yes’.

Their singing? It’s passable. Sincere, if not brilliant. Mocking the originals a bit, but also tacitly acknowledging that while the real Ball and Boe might be far from the cutting edge, they are great at what they do.

The originals wouldn’t be so successful without charisma, and so too is it with these comics, who are both stepping back from their usual shtick. No intense audience interactions from Riches – though the years of mastering such work gives his occasional forays beyond the fourth wall a bit of frisson. And by ditching his false teeth and tonsure wig, Kearns is both more and less like himself. 

For all the mucking about, they still make us invest in the relationship, ensuring the ups and downs packed into an hour have emotional resonance But never at the expense of excellent jokes and delightful turns of phrase crammed into every turn. In short, it’s a blast, with nothing taken too seriously except the drive to hit the next laugh, and quickly. That everyone in the audience is so thoroughly on board with the inherent absurdity of this concept gives the night extra sparkle, too. 

What would the real duo think? There are plenty of barbs based on those vague chimeras of them we hold in our consciousness, such as ‘Ball’ insincerely reading out fans’ letters or fostering a rivalry with old ‘Micky Bubbles’. But ultimately, both are portrayed as decent sorts, if far removed from this alt-comedy world.   

The subheading for this treat of a show vows ‘for 14 nights only’, which has already proved inaccurate, as this Soho Theatre run has been extended for a couple more performances to January 7. This Ball and Boe deserves to be a Christmas staple, at least – if not a part of the next Royal Variety Performance. 

» The Big Interview: John Kearns