The hundred-plus Batala drummers, sounding like the apocalypse, open proceedings and I pause to watch their complicated cornering manoeuvre into Westbourne Grove.
I revive at dusk and wander out. Concerned citizen journalists are videoing something through gaps in a hedge: police are subduing someone in a garden. But that means riot police and - oh joy - horses.
People are entranced. Pat-the-horse becomes the only game in town. 'I could stay here for ever,' says one boy as his girlfriend pulls him away.
One drunk boy offers to punch a horse. 'I really wouldn't do that,' says the rider.