I began this book reluctantly  I was deep into Hilary Mantel's Bring Up the Bodies, which is pretty much the exact opposite  but by the end I wanted to hand out copies to all those poor folks I see squirming their way through the squalid prose-dungeons of Fifty Shades. I wanted to launch a new British magazine especially for long-form journalism. I wanted to go out and round up a good few of the nation's so-called columnists and shame them into admitting that the weekly crap-farragoes that they are pretending to call careers will no longer do. I wanted to say "that's what I'm talking about".

What am I talking about? Pulphead is a collection of essays that appeared in various American magazines written by a journalist in his late 30s, whom almost nobody in Britain will know. But my guess is that those of you who like real writing (I know you're out there) will soon come to love John Jeremiah Sullivan  especially if he turns his talent to writing fiction, which, on the evidence of this collection, would not be too great a stretch. My stateside siblings tell me that he's already got a foot on the same escalator that took Foster Wallace, Franzen and the gang per aspera ad astra. Meanwhile, various people are calling him the next Tom Wolfe this and the new Hunter S Thompson that. Who knows? I'd say hold off a spell  he's simply not produced enough assessable work. But I certainly found this collection wonderfully engaging, lucid, intelligent, entertaining, interesting and amusing.

The first pleasure of Pulphead is the subject matter. There is the best essay you will ever read on Michael Jackson and the only essay you'll ever read on Axl Rose. There's the oddly emotional and disconcerting account of attending a Christian rock music festival entitled Upon This Rock. There's the story of Sullivan's time living with the mad old American writer Andrew Nelson Lytle, who late one night finally got around to touching the young John Jeremiah's genitals. There's a supreme piece of writing  part analysis, part paean  about reality television. There's an account of going to meet Bunny Wailer, the only surviving member of Bob Marley's original band, in Jamaica. There's a disarmingly convivial trip to Disney World. There's a wonderfully illuminating investigation into the lyrics of a pre-second world war blues song  and in particular what the word "kind" once meant  in the sense of "a little more than kin and less than kind". There's a moving and hyper-real account of Sullivan's brother's near death by accidental electrocution, a post-Katrina excursion to the Gulf Coast, some piquant pages on the Tea Party and a piece about the coming war between homo sapiens and the rest of the animal kingdom.

The second pleasure is the sophistication. So often the clarity of a writer's voice comes at the expense of a subtlety in tone. Not here. The two best pieces of the ensemble  Getting Down to What is Really Real and Upon This Rock  are written with such a well-judged balance of close-up love and objective report that they subverted my prejudices entirely and left me admiring Sullivan's way of admiring. I went into these chapters belligerently not giving a toss about reality TV and believing the Christian rock music scene to be the single most colossally redundant human phenomenon to date; I came out a changed reader. Sullivan had guided me through these alien worlds in a way that revealed to me their interesting geometries and their raisons d'être. What more can the writer do?

Not only do the essays engage, they are also richly informative. I finally understood the title of one of my very favourite songs  I and I by Bob Dylan  as a Rastafarian expression. And I found myself jotting down notes in order to seek out the songs Sullivan cited  one of which, Let Him Go, I am listening to right now. Again: what more can you ask?

But the greatest pleasure of all was the writing itself. There are essayists who rely on their subject to create interest and there are essayists who rely on their style. Sullivan deploys both. In The Last Wailer, he describes the notorious Jamaican drug lord and gangster Christopher Coke (oh, nominative determinism) as a "short, thick, somewhat pan-faced man, who keeps a low profile and always seems to be smiling at an inward joke". In the reality TV essay, he renders Richard Branson as "that weird and whispery mogul-faun, Sir Richard". Elsewhere, "knuckles are cubed with arthritis" and the music in a nightclub is "like a rabbit's heartbeat in the core of your brain". Everywhere, Sullivan's love of language, his skill and inventiveness, reminded me afresh of the delight of reading people who can actually write. And even when he didn't quite pull it off  the interior of a rented mobile home "smelled of spoiled vacations and amateur porn shoots wrapped in motel shower curtains and left in the sun"  I found myself greatly enjoying the failure.

I had only one reservation. Hovering somewhere in the coulisse of these performances, there seems to be an anxiety about authenticity. This manifests itself as an emphasis on what "actually" happened here, what the reader might check up on there, a habit of breaking out into bald film dialogue-style quotes as if to prove such and such was "really" said. In one story (the weakest), Violence of the Lambs  about the animal-human war  Sullivan adds a coda: "Big parts of this piece I made up" He seems angry about having to admit to fabrication "because of certain scandals in the past with made-up stories" and then writes a second postscript about new "facts" discovered. Sure, there are (adolescent) jokes in play here  about "fact-checking" journalism, about editors, about fabrication, about scientific horror stories  but there's also just straightforward bullshit at the expense of the reader. My take: expect a novel sometime.

Pulphead is a big, fat, frequently exhilarating collection of what in the US is portentously called "long-form journalism", aka magazine pieces. Books like this are always a hotch-potch, but here the potch is well and truly hotched. There are accomplished, more or less straight essays on the genius of Michael Jackson and the second coming of Axl Rose; there's reportage from Tea Party rallies and the aftermath of Hurricane Katrina; there's material on reality TV stars. But there's also a fine and scholarly piece about cave paintings in Kentucky, the iconography of the Southeastern Ceremonial Complex (aka Southern Death Cult) and the complex tensions between archaeologists and grave-robbers. There's a piece, animated by loving enthusiasm, about the crazed brilliance of Constantine Rafinesque, an early 19th-century French naturalist and anthropologist who knew Audubon and described natural selection before Darwin, yet mingled his results with bafflingly elaborate hoaxes and forgeries.

There's even a bizarre article  hard to tell how serious  about Sullivan's growing fear that animals are going to rise up and make war on mankind ("The Violence of the Lambs", of course). There's at least evidence that they're getting frisky. Crocodile hunter Steve Irwin's death by stingray wasn't a one-off, and in a Polish village in June 2000, the storks rose up and slaughtered the chickens. Also: "Elephants on the African savannah have been raping rhinoceroses, something that is evidently just as startling to zoologists as to the layperson". Probably quite startling to rhinoceroses, too.

What holds all this stuff together is the author's great curiosity (these pieces are written casually but researched to the nth degree), his warmth of tone and the sense under it of a sinuous intelligence. It's full of good jokes, tiny sharp bits of description, nuggets of gossip. He really knows music, too. You'd think everything that could have been said about Michael Jackson has been, but Sullivan finds ways of making it fresh.

The way he goes about things won't seem all that radical to most Brits. He's a practitioner of what you could call "process journalism"  where your travel arrangements and your relationship with your commissioning editor and your lousy attempts to read back your shorthand are either candidly or artfully or self-indulgently presented to the reader.

This kind of thing kicked off in the US with the New Journalism, but its most recent vogue has been over here. Practically every long interview you'll read in a Sunday paper now puts the interviewer front and centre; the investigative piece is often about the process of investigating as much as about what the investigator found out; and even at book length, research-memoirs such as The Hare with Amber Eyes have proliferated.

In Sullivan's case it's often the story of not getting the story, or half getting the story: of failing to interview Axl Rose; of falling out with Bunny Wailer over the logistics of organising a photoshoot; of interviewing a crackpot/maverick scientist but having him vanish with his story half told; of consulting a blues historian about an inaudible lyric only to be told: "Shit, I don't have any fucking idea."

Sometimes Sullivan  whose centre ground seems to be music-writing, but whose hinterland extends a long way in many directions  resembles Greil Marcus (indeed, a lovely article here spins off from Sullivan's efforts, as a magazine staffer, to fact-check a Greil Marcus piece); at others Jon Ronson (bemused, open-hearted and slightly nerdy innocent abroad); and at others the more recent ancestor of his style in US magazine writing, David Foster Wallace. Wallace is the strongest comparator in terms of his high/low vamping  the way nuggets of erudition coexist with a studiously offhand idiom. Sullivan is less studious and more actually offhand  there's more slack in the line than in DFW  but we're in the same territory.

As to the erudition, with Wallace it was literature, maths and grammar. With Sullivan, it's literature, geology and Bible quotes. Reporting from a Tea Party rally, he hears someone warning that "from each according to his abilities, to each according to his needs" originated with Karl Marx. He mutters to himself: "But that's from the Bible" (it's in Acts), and the woman next to him "looked at me like she'd just caught me sniffing my finger".

Like Wallace, he's fastidious about not trapping his responses behind the glass of irony. A piece on a Christian rock festival  which seems to augur a straightforward piece of college-educated-liberal culture tourism  sidesteps touchingly into a memoir of Sullivan's own teenage involvement with evangelical Christianity. The piece on Rafinesque ends up with an expression of passionate connection with the Frenchman's strange pantheism.

His engagement with religion is a pointer to one of the things that's most refreshing here. Most of the journalistic voices that seem to travel from the US are coastal. Sullivan, who grew up in Kentucky and southern Indiana and went to university in Tennessee, is declaredly a southerner. Strange things happen to him, too. That his marital home ended up being the set for a cheesy soap opera is one (fans still drive past taking photographs). That his brother died for a short time after being electrocuted by a microphone, an event subsequently featured on a TV programme hosted by William Shatner, is another. Sullivan describes the strange and faltering coming-together of his brother's zapped mind as he emerged from his coma. It's not all that far off being a parody of his own zipping-about style.

At one moment he tearfully describes having had a vision of the River Styx  "instead of Charon, it was Huck and Jim". Then: "the next words out of his mouth were, 'Check this out  I've got the Andrews Sisters in my milkshake.'"

 Sam Leith's You Talkin' To Me? is published by Profile.