Corbyn and Watson's musical differences on show in city of culture | Marina Hyde

To Hull for the launch of Labour’s “cultural manifesto”, a document that sounds like it combines the best bits of the Cultural Revolution and the Communist Manifesto.

On hand were Jeremy Corbyn, Tom Watson and the actor Samantha Morton, who nobly – if optimistically – declared: “Art is not an afterthought to what elections are fought over.” A statement slightly at odds with concurrent scenes elsewhere, where Tories were being chased by journalists shouting about social care. Or as Corbyn put it: “If George Osborne is at last doing something useful with his life, then that is to be welcomed.”

The self-styled Monsieur Zen was highly chipper for a man who’d spent the weekend being accused of being in league with the IRA. (Better than drawing them away in the cup, I guess.) Then again, at least Corbyn will stick by a distasteful position for four decades – Theresa May’s dementia tax U-turn suggests she can’t manage more than four days. “D’you know what?” beamed Corbyn of the general election campaign. “I’m enjoying every minute of it.”

Cut to Lynton Crosby clenching, cancelling all leave for the winged monkeys and whispering: “By the time I’ve finished with you, mate, you’re gong to look like you owe some Armenians money.”

Corbyn’s warmup act in the UK city of culture was Tom Watson, whose opening remarks made him sound dangerously like the Spinal Tap documentarian Marty DiBergi. A former Hull University student, Watson had been in town last night: “Does anyone know the small music venue called the Adelphi?” As Marty would say: don’t look for it – it isn’t there any more. Actually, hang on – it is still there, and Tom had gone along and bumped into the owner, who’d apparently said to him: “Are you going to try and blag your way in like you used to?” Good times.

Eventually, he yielded the stage to Corbyn, whose speech about Labour’s promised £1bn cultural capital fund was basically Katy Perry’s Baby You’re a Firework, if you stripped out the chorus and the bit with the roman candles shooting out of her bra. “Inside every one of us,” Jeremy explained, “is a poet, a writer, a singer of songs, an artist.”

Even inside Conservative cabinet ministers? Or is the exoskeleton too rigid? Unclear, though the digression was helped by the fact it was being delivered to party activists who believe that inside every Tory is something similar to that thing inside a Dalek.

“Under the Tories, the arts and cultural institutions have been forced to absorb huge cuts; under Labour, they will get the investment they deserve.” In retrospect, then, it felt slightly odd that Labour chose to launch the policies in a Hull arts space that has just received a £700,000 government grant from the coastal communities fund, a Tory initiative. But think of this as what Alfred Hitchcock called an “icebox scene” – a plot hole or inconsistency that only hits you “after you’ve got home and are pulling cold chicken out of the icebox”.

The more intriguing inconsistencies, perhaps, are the musical differences between the Labour leader and his deputy. There were warm-effect words for Watson from Corbyn. But to watch the two of them away from the podium is to see some of the most awkwardly dysfunctional body language since Glenn Frey of the Eagles spent a 1980 political benefit concert openly counting down the number of songs that remained on the setlist before they could get offstage and he could lamp Don Felder. The audience were treated to Felder informing Frey: “Only three more songs till I kick your ass, pal,” and Frey replying “Great, I can’t wait.” “We’re out there singing Best of My Love,” Frey recalled later, “but inside both of us are thinking: ‘As soon as this is over, I’m gonna kill him.’” In the event, Felder ran straight into a limo and the Eagles didn’t play together again for 14 years.

Obviously, it’s going to shake down a little differently with the Labour roadshow when this setlist is finally played out on 9 June. My sense is that Labour HQ’s post-election diary is simply blocked out with one giant scrawl: Waco. Anyone not currently delirious on Labour’s current poll rally would be wise to expect some kind of compound siege, as the Branch Jeremians decline to accept the endgame laid out for them by Watson’s bungling FBI swat forces.

For now, though, these remain just the undertones – and Corbyn was at his most magnanimous. Free museum entry, he said, “is something we’re proud of in the Labour party, something Chris Smith achieved when he was our culture secretary in 1997”.

Crikey – had he finally found something to praise about you-know-who’s Labour government? No doubt normal service will be resumed in due course. After all, the default position of the Corbynistas on Blair’s act is perhaps best summarised by David St Hubbins of the aforementioned Spinal Tap: “They were still booing him when we came on stage.”