Take a look on Google Earth for a model of the 360° stage, in situ, at the venue... about a week ahead of each show. Soldier Field, Chicago, is a good place to start your search.

The model might be red, green or blue - corresponding to the three different steel teams who leapfrog each other from city to city to build the stage in each stadium.

'We thought it would be interesting to put up on Google Earth a piece of portable architecture, which is what this structure is, ' said 360° Tour Architect Mark Fisher, when we talked to him a few weeks back. 'In a way it's got no practical purpose... except that it's fun!'