A fortnight later and the tune in my head is still there; less insistent, less forceful, not as loud, but still beating away like a pulse.
You don't forget the Binche carnival easily.
The parade on Sunday seems ordinary enough; groups of revellers in costume, with their brass bands. There are devils, ghosts, musketeers, peasants, little Chinese mandarins, huge contingents of Smurfs (this is Belgium); there is Michael Jackson, there is Che Guevara - no, there are at least a dozen Ches - but sadly no Elvis.
But it's not choreographed; one contingent is mainly Che Guevaras, but also contains a couple of phantoms and some peasants, and a couple of guys in strange Tommy Cooperesque outfits with fezzes and stripey waistcoats. Every one carries something in his right hand; a placard, a tray with champagne bottle and glasses, a billhook, a basket of strawberries, a huge plastic foam rifle. From time to time, marchers drop out and wander into one of the local bars, or share a bottle of beer and a fag with a friend in the crowd, or stop to exchange kisses on the cheek with their acquaintances. It's all a bit shambolic, and that's the case for everything that goes on during Carnival; timings are approximate, and any procession is likely to include numerous beer or champagne stops.
They don't really dance, either. They shuffle, and turn round and round within their company, and punctuate the music by lifting whatever they hold in their right hands; but that's all. Not the shimmying samba of Rio or the rhythmic verve of calypso or soca.
Yet there seems to be one rule that isn't transgressed; they only play one tune. There are 26, some people say 27, tunes allowed in the entire carnival, and tonight somehow they're only playing one. When I went to bed, it was playing in my head, and it carried on doing so for the next fortnight.
Fast forward to the ramassage, in the early hours of Shrove Tuesday morning. It's still dark; Binche's houses loom dark in the orange lamp-light. From a long way away we hear the shrill, plaintive tone of a clarinet playing a snatch of melody. Somewhere else, a bass drum starts; bom, bom, bom, bom, interminable, like a death march.
Down below the great walls, a first detachment of Gilles lumbers, their white-covered heads stark, their drummer pushing them forwards. Their inexorable march, the clack of their wooden clogs on the granite setts of the road, the fierce sharp rattle and snap of a snare drum from one of the side streets; it is all faintly sinister.
They stop at a house, dancing on the spot. The door opens. Time for champagne. (It's five o'clock in the morning.) Glasses are handed out. We wait. Some time later, they set out again. Now there are six Gilles, instead of five; like giants or ogres, wearing those huge clogs, their torsos stuffed with straw, their suits covered with symbols - crowns, and lions, and stripes and flags, all in the Belgian colours of black, yellow, red.
Glimpses of interiors every time a door opens make us feel as if we're in a gallery of Vermeers, but with starker lighting - a contrast to the dim streets. One house seems right out of the nineteenth century with its caged canary, a crucifix and a two years out of date calendar on the wall; another is a modern artist's house, full of bright stained glass and polished wood. By the time the procession reaches the main street it's nearly seven-thirty, and the Gilles are massing outside the bars, and inside the bars, holding glasses of champagne in their hands. The Gilles drinks champagne, and eats only oysters and salmon; this is the last of the fat days, before the rigours of Lent.
One little boy Gille is accompanied by an even smaller boy with a snare drum, and his mother - a procession of one. (How could you not smile?) A Gille goes everywhere with a drummer. That's one of the rules. In the crowd, two Gilles decide to visit their friends in the next bar - confusion, as they try to find a drummer, and then the shattering fusillade of noise as they set out, bludgeoning their way across the packed pavement outside.
Up by the station, the Gilles are gathering in their hundreds. And at last, on go the masks, the symbol of Binche, with their sightless green spectacles and curly painted moustaches; and the Gilles are terrifying, battalions of them all marching on the Town Hall. In the afternoon, the terrible Gilles show their softer side; the masks are laid aside in favour of tall ostrich-feather hats, and the bundles of twigs they carry in the morning are replaced by baskets of oranges, which they throw into the crowd.
Standing on a wall to get a better view, I'm next to a red devil. Aged about eight, I think. She catches fifty oranges; I catch none.
And this is only the second parade - there's another to come, by lamplight, that evening. In the narrow streets, the Gilles dance to the red light of flares. The carnival started in the early hours, and it doesn't finish till the fireworks are over, at nearly eleven; and even later, as we head for our car, we can hear the brass bands still playing.
I can still hear that tune. I don't think it will ever go away. It will fade, it will become less insistent; but it will always be a part of me, and my feet will somehow always know that rhythm.