He is 70 years old, Devon born and bred. The mural spans three walls of the Plough Theatre in Torrington, where he directs drama enacted by the traumatised, the disabled and those who thought they had no talent.
Culture? The goings-on he paints are still going on, part of the living culture of 11 villages within a 30-mile radius of Torrington. He says: "If the people who live here have been falling foul of people from the big city, who told them it was a cultural desert, it was because they didn't know what goes on. Now they do."
What does go on in North Devon is not always divulged by the tourist brochures. Even Mr Sprague had a job finding out. He visited village shops and pubs. "What goes on here?" he asked.
Well, he was told in Hatherleigh, there's the running of the tar barrels. But when? "On 9 November," said the postmaster, who he had telephoned in frustration: "there's the carnival at 6.30 then the tar barrel running - but," he let slip as Mr Sprague was about to put the receiver down, "it's not the real thing. That takes place at 4.30 in the morning. When you see it, you'll see why."
The real thing, Mr Sprague found out under pouring rain at the appointed hour, began when a man wearing yellow oilskins over his pyjamas stood at the top of the hill, sounded a klaxon and handed out handbells. Villagers appeared carrying pails of water.
Suddenly, a wooden sledge laden with three tar-filled oildrums roaring flame through holes came crashing down the hill, cannoned off the kerb then accelerated out of control on the slippery surface as pails of water were thrown over the singed and stumbling men who had let go of its ropes.
The mobile furnace ended up in the car park where wood was thrown over it to make a bonfire. Then the streets emptied. The episode had lasted 10 minutes. But it will last a lifetime or two on the walls of the International Centre for Psychodrama and Sociodrama.
It's not high culture. It's not warbling opera or clever conceptual art. Mr Sprague's concept of culture is basic: it's what comes out of the soil and the climate. The river Umber in his village of Combe Martin yields red, brown and burnt umber, a basic ingredient of the paint used by Turner, who stayed in Bideford. There used to be 27 breeds of sheep in the region. Now there are 50. The local culture supports them, as it does his two Devon Red cows who sport posters saying "Cull the politicians, not me".
He says: "This basic culture is welcome soil for the professional theatre that performs here and all our other art forms at the Plough."
As for Combe Martin's red-jacketed grenadiers with yellow dunce caps who spend four days a year shooting to death with blank cartridges a volunteer Earl of Rhone: they are probably enacting layer upon layer of culture. There were no such grenadiers when the local Chichester family hired a killer to do away with the detested Earl - probably a 16th-century Earl of Tyrone, not Rhone, who tried to impose Catholicism. Who knows why men dressed as grenadiers still enact it?
But when, finally, the Earl is ritually thrown into a sea whose farthest coast is Ireland, some deeper sense is aroused - of evolution from water. Mr Sprague says: "That's what I mean by layers of culture. These things are not nostalgia. They are even pre-pagan. They arouse the primitive in us."
Beaford's wheelbarrowed "revel mayor" is a political parable for our times. By tradition, the chosen mayor is always one genuinely honoured in the community, whether vicar or roadsweeper. But, having been barrowed in triumph, in the end, he is dumped on the village green. Every culture, everywhere, treats its elected leaders the same. Major and Blair take note.Reuse content