They keep mixing it up, with more changes to the set list for the second show in Chicago last night.

City of Blinding Lights seems to have settled back into its role as the show opener now the band are back indoors. Vertigo, coming hard on its heels, only ignites the frenzy further. But there's no point in predicting a set list at this stage of the tour - you never know whats going to happen.

After a whole series of surprises for the opening date in Chicago, tonight most of those innovations were missing ­ instead we had Wild Horses (in for the first time since the summer) and Original of the Species, which is hardly ever played and all the more a treat when it is.

'Heres something for the train spotters and plane spotters', explained Bono, by way of introducing introducing Wild Horses from from 1991's Achtung Baby.
'This is a song that we havent been playing for a while ­ I dont know why
its kind of simple really'.

It's also one of the great sing-a-long moments of the night and inspires Bono's comments about availability for miscellaneous life-stage rituals.
(Please, no requests to U2.Com for the band to perform at your funeral ...It's difficult enough keeping up with the wedding invitations.)

'You're dangerous, 'cos you're honest.
You're dangerous, you don't know what you want.
Well you left my heart empty as a vacant lot
For any spirit to haunt.

You're an accident waiting to happen
You're a piece of glass left there on a beach.
Well you tell me things
I know you're not supposed to
Then you leave me just out of reach...'

During Beautiful Day Bono raps enigmatically about being 13 and listening to music in your bedroom before tripping into Sgt Pepper. 'Wassup Edge?' he asks, as the guitarist picks up the notes to Miracle Drug. 'I keep telling people The Edge is from the future and Dallas Schoo. They're also from another galaxy and another planet in the future..
'These are beautiful notes, when Edge's space ship came to the north side of Dublin it was playing that tune. Am I right? Adam, Larry and myself watched his space ship landing...'

And so the Edge myth develops, this time we learn that Dallas arrived with him. What more will future shows reveal? How come a myriad of U2 biographers have missed this crucial information, so essential to the mysterious origins of U2?

Sometimes is followed by Yahweh, again played on the main stage after which the proceedings go stratospheric. Not only is Miss Sarajevo again in the set, but Bad opens the first encore, followed by Original of the Species.

'Everywhere you go you shout it
You dont have to be shy about it, no
And youll never be alone
Come on now show your soul
Youve been keeping your love under control

Everywhere you go you shout it
You dont have to be shy about it..'