"I want you to write me a track entitled "Bus Meat". I want you to write it as if you were scoring a music video, which I shall now roughly describe. There is one other condition: there must be harpischords. Good luck!

The sun rises above primeval moorland; we are somewhere windswept and rugged, a place where meadows are dotted with hardy wildflowers and snow rimes the lee of stones.

We see flashes of tyres rolling on broken ground; sun glinting from wing mirrors, red-painted metal, and exhaust pipes panting fumes into the cold dawn.

Wide overhead shot: a London bus, driving wild across the tundra. There are no passengers, there is no driver. It is a wild animal.

As the view widens, we see the bus is pursued by a small group of human figures, on foot, maybe 50m behind it.

We cut to the humans; they are as rough and weatherbeaten as the land, with wild hair and scarred faces. They are dressed in torn upholstery and roof-lining, sewn with beaten metal plates and strips of tyre.

The humans run hard; they are gaining on the bus. Their leader runs out ahead and hurls a spear; it lodges in the rear tyre of the bus, which blows.

With the bus exhausted and running on only three wheels, the humans begin to catch up and surround it in a loose group. It is in trouble now.

One young warrior runs in with a blade to go for the bus's intact rear tyre - but he has misjudged the animal's strength. It swerves and smashes into him, sending him rolling across the grass.

The leader of the hunters rummages in his pack, and withdraws an airhorn, which he sounds. After a moment, it is answered by horns from the distance.

Engines rev, just round the curve of a hill - a pair of Vauxhall Astras emerge, wild and hungry, also driverless. They match pace with the humans, who pat them as they pass and send them on to take down the bus.

The cars sideswipe the bus, dashing away before it can retaliate. They slam into its side, nudging it into sharp rocks, and it honks its horn in dismay.

With the bus wounded, one of the Astras circles and hammers head on into its side, crumpling the bodywork.

The bus is stalled; the cars reverse and ram it over and over again, while the humans leap onto it with blades.

Cut to the interior of a cave, at night. We see Bus Meat roasting in a fire. Chewing and nodding his head in satisfaction, the leader of the hunters pulls the roasting hunk from the fire and tosses it to one of the Astras, revving contentedly in the firelight.

Slow zoom out, as the humans settle into their sleeping bags for the night around the fire. Past the Astras, the stripped remains of the Bus lie in the darkness. A pack of mopeds squabble over the last pickings."