Subtlemob on Madero Street

At precisely 8pm this evening, halfway along a busy pedestrian street which runs between the Zocalo and Palacio de Bellas Artes in the centre of town, Liz and I plugged in our earphones, selected an MP3 which we'd been invited to download earlier and pressed play. We were 'in' As If It Were The Last Time, a subtlemob by Duncan Speakman.
I've done it twice before, in Tokyo and Xiamen. They're strange events. Most people out walking & shopping are oblivious to the fact that there's an 'event' going on around them, but those that are participating spot others doing so and it becomes a special, semi-private, semi-public thing.
A voice gives various instructions, there's music, you walk, stop, look at everyone else, try to remain invisible. You are little islands in a river of humanity flowing past. And you finish with a slow dance. It's of course the best bit. The street becomes alive with dancing (well, shuffling) couples and it's only then that the 'event' becomes visible to everyone else. Puzzled looks are exchanged, people smile wondering what on earth's going on. An elderly couple stopped and danced with us, even though they weren't 'part of it'. And then it's over and everyone disperses, back to their lives. But for half an hour we shared something.