There comes a point during tonight’s set when Beck barricades the front of the stage with yellow tape with “Crime scene do not cross” printed on it. His guitarist Jason Falkner, meanwhile, is lying on his back by the amps grinding out feedback; a few yards away, bassist Justin Meldal-Johnsen is collapsed over the keyboards. This, then, is the suitably dramatic climax to Beck’s main set – which has remarkably proved to be a triumph of the will against the weather. Beck and his band took the stage at 7pm, in full sunlight, wearing blacks and greys: under such circumstances, it was hard enough to make themselves seen, let alone convincingly fill such a large space. Nevertheless, for the next hour Beck deploys every resource at his disposal: the funky freak power of “Devil’s Haircut”, the smouldering Latino swagger of “Qué Onda Guero”, the hip hop beats of “Hell Yes” and “Soul Of A Man”’s sludgy, Sabbath-like riffs. Elsewhere, there are digressions into library music, surf guitar, ‘60s chamber pop, ‘70s soul and ‘80s hardcore. “Thanks for sticking it out and spending a few precious minutes with us in a field,” he says in a rare let-up in the show’s pace.

Of course, Beck has always been one of music’s most progressive and eccentric shapeshifters – but evidently he is on a roll at the moment. Looking back, Beck’s trajectory over the last 12 months has been a period of subtle recalibration. Prior to the release of Morning Phase – and its Grammy win in February – Beck’s career appeared to be drifting out of focus. It had been six years since his previous album, Modern Guilt, and rather than knuckle down to the business of recording a follow up, Beck instead directed his attentions to other people’s music: producing the likes of Thurston Moore and Stephen Malkmus and covering albums by Leonard Cohen, INXS, Skip Spence and the Velvet Underground in his collaborative Record Club project. Even 2012’s Song Reader took the form of sheet music rather than a conventional album. Reflecting on that period before Morning Phase, you might wonder whether Beck wanted to do anything other than create his own songs. But palpably Beck in 2015 is far more engaged than in recent years. “New Pollution”, “Loser”, “Sex Laws” and a marvellous extended “Where It’s At” (complete with lengthy harmonica breakdown) are delivered with wit and a deftness of touch. Intriguingly, neither Beck nor the Strokes are on the promo circuit right now – Beck doesn’t even play his current single, “Dreams”. Beck explains his friendship with the headliners stretches back 15 years: today, he is happy “playing a few tunes to warm up for the Strokes.” If that’s the case, it’s a nice gesture, which adds to a sense of goodwill emanating round Hyde Park this evening.

The Stokes have suffered from their own set of creative frustrations – albeit ones different to those experienced by Beck. Essentially since Room On Fire, the Strokes have struggled to revisit the heights of their debut: their progress has been hampered by the jostle to establish solo careers, internal strife and a kind of weirdly non-committal approach to their principle career. Indeed, this is the Strokes’ first UK date in five years and nearly two years since their last album, Comedown Machine. Admittedly, Albert Hammond Jr’s recent comments on BBC 6Music that this show might be their last felt like the latest twist in the band’s weird, dramatic narrative. But if this is the end for the Strokes, tonight is a marvellous way to go out. Opening with “Is This It?” and “Barely Legal”, they cut back to the short, sharp thrills of their debut. But conspicuously, the sound is tight and muscular: the thin, metallic production of Is This It? now expertly filled out. Certainly, the rest of tonight’s set is full of hellacious energy: heavy guitars, howled vocals, metronomic drums, thunderous basslines. For his part, Julian Casablancas has some remarkable hair going on: essentially, he’s grown a mullet which has been dyed red down one side, as if someone’s spilled a tin of paint over him just before he came on stage. Elsewhere, drummer Fab Moretti sports a tangle of curly hair and a beard that makes him look like a young Tony Iommi; the hair shocks extend to bassist Nikolai Fraiture, who appears to have had his hair modelled on a Norman soldier’s helmet. Unable to compete in that department, Hammond Jr opts instead for a bright red jumpsuit.

As the show proceeds, rumours of the Strokes mortality appear increasingly premature. Casablancas’ between song-patter – largely limited to “What’s up, sexies?” or “What’s going on?” – takes a hysterical turn before “Someday”, when he introduces a guest spot from Shabba Ranks. Sadly, he’s only joking – alas, the indie/dancehall crossover will have to wait – but it hardly seems appropriate behaviour for a man preparing to deliver Last Rites on his band. The newish songs – “Welcome To Japan”, “Under Cover Of Darkness”, “Machu Picchu” – sound strong alongside “Reptilia”, “Hard To Explain” and a propulsive “Last Nite”. Though it may be two years since they last released a record, the Strokes still radiate a reassuringly healthy disposition. “London, I like what you’ve done with this place,” says Casablancas approvingly as he looks out across Hyde Park, the sun at last going down.

Follow me on Twitter @MichaelBonner

Beck played:
Devil’s Haircut
Black Tambourine
Think I’m In Love/I Feel love
The New Pollotion
Qué Onda Guero
Gamma Ray
Hell Yes
Soul Of A Man
Blue Moon
Lost Cause
Go It Alone
Loser
Sex Laws
Debra
E-Pro

Encore
Where It’s At

The Strokes played:
Is This It?
Barely Legal
Welcome To Japan
You Talk Way Too Much
Someday
Heart In A Cage
Hard To Explain
Automatic Stop
Vision Of Division
Last Nite
Reptilia
Machu Picchu
Under Cover Of Darkness
One Way Trigger
New York City Cops

Encore
Juicebox
You Only Live Once
Take It Or Leave It

The History Of Rock – a brand new monthly magazine from the makers of Uncut – goes on sale in the UK on July 9. Click here for more details.

Meanwhile, the August 2015 issue of Uncut is in shops on Tuesday, June 23 – featuring David Byrne, Sly & The Family Stone, BB King and the death of the blues, The Monkees, Neil Young, Merle Haggard and more