Kings of Leon, Hyde Park, London<br/>tUnE-yArDs, The Haunt, Brighton

The US rockers used to be warm and engaging, so why have they become such whingers?

There's a scene in the film 24 Hour Party People, rooted in fact, in which the Happy Mondays kill thousands of pigeons by feeding them bread dipped in rat poison.

Watching Kings of Leon, one finds oneself daydreaming about some latter-day Shaun'n'Bez dosing up a squadron of cooing kamikazes with Ex-Lax pellets and waving them off to Hyde Park to do their worst.

Because, let's face it, the incident in St Louis last summer when a flock of feathered ninjas deposited guano down their gullets is the most interesting thing that's happened to the Followill family for years. Well, apart from the conflagration aboard their coach in December which forced them to call off their O2 show, launching innumerable "Yooouuu, your bus is on fire!" jokes.

As an early-doors "Molly's Chambers" reminds me, when I first met KoL in San Francisco in 2003, I rather liked them. Pentecostal adolescents on their first adventure away from home, smoking irreligious substances in the back of the van (see, that's how blazes start), they were wide-eyed at all life's sudden possibilities. Before long, their every debauched desire sated a thousandfold by life on the road, they became at first jaded, then downright misanthropic, culminating in the infamous performance in 2009 when singer Caleb gracelessly berated the Reading Festival crowd for not being noisy enough. "We know you're sick of Kings of Leon," he bitched. "We're sick of Kings of Leon too. But we get up here every night and ... we've worked hard to be here!"

Britain loves them more than their home country ever will, and what do they give us? Scowls and strops. Tonight they're in a slightly better mood, with Caleb blurting a simple "Kings of Leon!" after the first few songs, like Timmy from South Park. There's a little cursory banter later: "I wrote this song about all of you," (before "Fans"), and a toast to recently deceased Jackass star Ryan Dunn. But for a band operating in a genre – southern rock – whose selling point is its warmth and humanity, there's something strangely frosty and unengaging about this band.

Down the front, people are being hoisted out for their own safety, but in the rest of the field ambivalence reigns. A crane camera, looking like the grab-arm from a seaside soft-toy machine, swings low over a crowd that largely resembles deep-sea fish in tracksuit tops, searching for telegenic displays of enthusiasm. But most of them are mainly here for one song – I'm nearly crushed in the stampede to the exits after "Sex on Fire" – and their enthusiasm for KoL, when vox-popped, never goes above "Yeah, they're all right ...". If we've learned anything, it's that the key to ubiquity isn't greatness, but a finely tuned optimum level of yeah-they're-allrightness.

I'm inclined to agree. The only fireworks tonight are literal ones, launched from a cherry-picker backstage. This un-Skynyrd bop doesn't blow me away. Kings of Leon? Yeah, they're all right.

In a world where any self-consciously quirky female in a feather headdress gets called "the new Kate Bush", Merrill Garbus of Tune-Yards, or, as they're annoyingly rendered, tUnE-yArDs, might be the real deal.

The New Englander's surrounding crescent of musicians are literally peripheral, although her film-noir saxophonist threatens to steal the show. Wearing flapper pearls and puffier shoulders than Deb's prom dress in Napoleon Dynamite, she's all but a one-woman band, simultaneously drumming standing up, strumming a ukulele, and rasping into dual mics to allow live sampling so she can effectively sing "in the round" with herself.

The end result is multilayered, blending elements from afrobeat, bebop jazz and post-punk, and on tracks such as current single "Bizness" it's entrancing. Garbus is extraordinary. If only she'd leave that damned sHiFt-KeY alone.

Next Week:

Simon slips on his diamond-soled shoes to see if his namesake Paul is still crazy after all these years

Rock Choice

The unbranded Hop Farm Festival brings The Eagles, Roxy Music and The Human League (Fri); Morrissey, Lou Reed and Patti Smith (Sat) and Prince (next Sun) to Paddock Wood, in Kent. And the extremely branded iTunes Festival kicks off with Paul Simon at London's Roundhouse. (Fri).