The thinking man's rock star

Peter Gabriel has just bought a new place in Sardinia, holiday island to half of Italy and the entirety of the English Premiership. "Li Capanni" (The Little Cabins), as its name suggests, is not a rock-star mansion with rococo fountains and stable-space for six Ferraris. It's a family of a dozen or so small, off-pink, stucco cabins nestling on a handful of acres tumbling down to a tiny sickle of Mediterranean shore.

The cabins – which until a year ago served as the sleeping-quarters of a basic hotel compound – are grouped haphazardly around a larger central building where food is cooked and eaten, and are linked to it by a web of concrete pathways that curve and plunge abruptly among trees and bushes. You can disappear down a path and not be seen for hours if you like, then reappear somewhere else, sudden as a snake.

Gabriel is considering making use of Li Capanni as a "think tank". His chums from the worlds of technology, design, philosophy and psychology will come here to rub brains. There are no TVs or sofas; only walls, showers, toilets, tiles, beds, snakes, the sea and the weather. Good for the soul, you see.

Currently, it is being used as a base for family operations. This includes the Gabriel family of musicians, their partners and children, their crew, their housekeeper and a man from the local council who materialises every day like a smiling magus, bearing mushrooms, olive oil, wine and unnamed things encased in tree bark. Gabriel tools around amiably in shorts and sandals, sploshing in the sea with his one-year-old, muttering in passable Italian to the housekeeper, sometimes disappearing altogether.

There is a kind of purposeful drift to his activities. You would hope so. In three weeks, he is to embark on an American tour. It will be a full-blown affair, involving band, lights and theatrical stage show, designed and choreographed in cahoots with his old mucker the Canadian director Robert Lepage, on a theme extruded from the subject matter of the new album, Up. They haven't yet nailed down what will happen in the show, or how. But Gabriel has decided it will take place on two stages, representing Heaven and Earth. Up and Down, you see. And that is about as far as they've got.

There is little sense of panic at Li Capanni. Up the road, Gabriel is rehearsing the music. He has borrowed the gymnasium of a local school and is busy bedding in a brand-new keyboardist, Rachel Z from New York. "She has to learn in a few days, using two hands, what I've spent years putting together with one finger," he muses. She looks slightly anxious and watches him all the time.

I've always wanted to do this: watch a really good group rehearse. It appeals to the Dorling Kindersley part of my soul, the lobe that likes to experience things in bits: exploded, or not quite finished, with all the works hanging out. If I'm honest, the music I like best is like that. So it has always amazed me that I enjoy Gabriel's music as much as I do, given that his records are tweezered together and highly finished, utterly resistant to counter-penetration.

What I get to hear in the gym, though, is not Dorling Kindersley but the last stop on the production line – the finished product poised on the ramp in a resolved state of technical completion, ready for testing. All the parts have been fitted together, the paint job completed, the wiring done, the plastic seat-covers installed to safeguard your personal hygiene. "All we need is the fuel," says Gabriel. "And that comes from performance. We're 90 per cent there with the parts. Now we need to get the magic in."

I'm given a set of headphones so that I can get the full mix, and I flop down next to a vaulting-horse on a thick mat, reviving ugly muscle-memories of a gymnastic career that went flump-gasp around the time Gabriel first sang "Harold the Barrel". The sun is beginning to smash through high windows. Gabriel is not singing. He's saying the words, to save his voice. And the others are saving their jam, getting the notes right, occasionally glancing down at the computerised song "maps" on the screens at their feet, basically doing an ultra-intense technical walk-through.

Their concentration is almost as loud as the music. And at the end of each song, hush descends as Gabriel mutters incomprehensible notes, Rachel nods a lot, and then they kick off again. "Darkness", "Red Rain", "Growing Up", "No Way Out", "Mercy Street", "My Head Sounds Like That", "Sledgehammer" (retooled for added funk). It's like watching an engine working on a testbed. There is no chassis or wheels to move it along, but all the parts are flying.

Then the local council turn up. They start to materialise at the back of the gym and flood slowly along the back wall, among the weights and bars, talking out of the corners of their mouths and nodding at the band. One gives Gabriel a sheepish little waist-level wave with his fingertips. Gabriel beams and tips back his head in greeting. It's the mayor.

"Buon giorno!"

Convened by the Magus of the Mushroom Basket, the two parties descend on one another with great cries, the 16 councillors and seven band-members coming together in a great crash of bonhomie. There is much flesh-pressing and gurning, and a big formal photo of the two parties intermingling like mad. "Thank you!" "No, no, no – grazie mille!"

And then, as suddenly as they came, the councillors disappear, pausing only to shake my hand and say thank you as they leave. I get up off my gym mat and thank them cordially in return. It turns out that, only a week or so previously, at the festival of the town's patron saint, Gabriel and band had filled in heroically at the last minute when the local hit-makers pulled out of the gig in the town piazza. They had gone down rather well. "We did it partly to say thank you for letting us come here and use their amenities," says Gabriel the next day. "So the council came to our rehearsal to say thank you back. Very nice. Especially that they all took the trouble to come."

Gabriel's dad was a big cheese in electrical engineering, with a particular jones for the future potential of cable TV and fibre optics. Peter is a chip off the old block in at least one way: he can't resist the possibilities raised by a network. His "think tanks" and his Real World studios, his unrealised theme parks and his human-rights Witness programme, his interactive therapeutic technology and his interface with the mayor – the list goes on – are all networks of one kind or another, conceived at one level to connect people. Time will no doubt deem these "side-projects" to be as central to that elusive Gabriel thing as his crunchy, semi-opaque music and his family of cabins on the Sardinian shore: a web of pathways in thick undergrowth into which he can slip like a snake and not be found.

You may have read about Gabriel jamming with apes. You may or may not have sniggered. Well, I've seen the footage. Gabriel sits and doodles at a keyboard in some research laboratory in Atlanta, Georgia. A bonobo ape comes into an adjoining chamber and sits at a keyboard. It starts picking out notes. Faceless behind a window, Gabriel keeps noodling. And then, in the same instant that you're thinking, "So what am I listening to here – this is hardly Herbie Hancock?", it dawns on you that the ape has sidled into harmonic coalescence with our hero. The furry bugger is playing in the same key. Then Gabriel gets his rhythm section in and they kick off something that really does sound like Herbie Hancock, and another ape comes in and starts making like a conga-player on the keys. This bonobo is playing in rhythm.

And it is impossible after watching it to hold Gabriel's relentless eye-contact and not nod with feeling when he paraphrases Chomsky on how the human brain evolved a department dedicated to language and syntax, and the way that "it's obviously not an exclusive human province."

"My motivation for doing it", he says, his words coming out as they customarily do, like tickets out of a pay-and-display machine, "is simple curiosity about other intelligences on the planet."

It's the done thing at Li Capanni to swim in the middle of the night. It's pitch black; you plunge in and you bob and bump blindly with all the other bodies in the water, like apples in a barrel with the lid on. The point is to mess with the phosphorescent plankton. You swoosh your arms and legs around in the water, stick your head under and watch the light show, which is better than the effects in any pop video you've seen. It's nature, it's science, it looks great, and it's right at the bottom of Gabriel's garden. It is surely only a matter of time before he starts getting curious about the plankton. Not tonight, though, because he's up at the main building, signing a giant pile of CDs for the Mushroom Magus, who is still smiling fit to bust.

'Up' is out now on Real World records