The setting was a giant marquee in a rather unfashionable district. All the elements were ranged against us. Torrential rain poured down throughout the evening. As we approached the venue, scores of armed police – partnered with fierce chained Rottweilers – milled menacingly about. Their brooding presence suggested we were the problem.

Inside the brightly-lit marquee, 5,000 or so fans massed into the steep tiers of the stands. The atmosphere was infused by the camaraderie of outsiders gathered as one – like a political demo in a totalitarian state. Its location in a sodden field felt like a land grab under the nose of a paranoid dictatorship.

The energy generated over the next few hours lacked the celebratory atmosphere of the London event, but offered something tangibly more powerful. It was a mission rather than a performance. Our safety in numbers and the warm dry conditions lent the marquee security and comfort in contrast with the tension and deluge outside. Inside, like an angry righteous demagogue, Manu whipped the crowd into a frenzy.

He had a theme. The Colombian president was looking to convince the population of the benefits of a free trade agreement with the US. Enthusiasm for the deal was divided on political lines and the Bush-Uribe friendship gave the US a foothold in the continent that contrasted with the hostility provoked by the northern giant elsewhere in the region. Mr Chao was not a supporter. The deafening chorus of roared responses to his rousing calls suggested the audience were of similar mind.

As the crowds dispersed at the concert’s end, the rain had abated somewhat and the fierce sentinels of the state were less prevalent. Their intimidation tactics had failed, but we were left in no doubt about our place.