Not to mention Walk On and Discotheque and Bad as U2 ring the changes in the
windy city.

'We wanna play a song that we haven't played on this tour,' raps Bono, as the band come out of a beautifully moody version of The Ocean. 'You haven't all been to a show now have you?'

No time for a survey as Edge, on acoustic guitar, is already strumming the opening chords and Walk On is with us, first time since 2001 when it was the show-closing show-stopper on the Elevation Tour.

'And love is not the easy thing
The only baggage you can bring...
And love is not the easy thing....
The only baggage you can bring
Is all that you can't leave behind...'

'You know the lyrics,' Bono says, laughing to Edge. 'It would be great if I knew the lyrics.' At which point, the lyrics are helpfully pushed before him and he's back on song.

'You're packing a suitcase for a place none of us has been
A place that has to be believed to be seen
You could have flown away
A singing bird in an open cage
Who will only fly, only fly for freedom...'

'Its okay to try stuff is it?' he asks at the close of the track, 'Well, this one will never go anywhere.' And the night is a Beautiful Day in Chicago, a show full of surprises and experiments. They stuck with some of the ideas they tried out in Toronto (Discotheque), they pulled in some of the successes from the European leg (Miss Sarajevo, Bad) and they whipped some rabbits from the hat (Walk On, The First Time). There are new words of explanation too, new meditations on where songs have come from and what they might allude to.

'Thanks for coming out, somebody much wiser than I - I think it was Chrissy Hynde from The Pretenders - said to me 'All girls stay age 13 and all boys stay age 8.' And this isn't a therapy session, but this is a song about my father..'

Feels like the band are really up for seeing what works and what doesn't tonight, so just when you expect Love and Peace you find the psalm-like Yahweh arriving with no introduction and a solo Edge. Larry's already in position at the tip of the ellipse for Love and Peace, as the red hearts race up and down the illuminated curtains surrounding the stage and the
energy rises for Sunday, Bullet and Ms Sarajevo.

This last is interesting because the audience seems slightly stunned by it - maybe because it was never a single release in the US. (Actresses Ashley and Winona Judd are both here by the way, and loving it.)

'I am because we are'' explains Bono, translating a Zulu word - 'ubuntu' - learnt from Archbishop Tutu. 'I couldn't help but think of this when looking at the pictures of Louisiana... and we saw this with 9/11 and we saw this with the the hurricane ­ that¹s when we discover how great this country is. That's why Larry Mullen, The Edge, Adam and myself are such fans of this
idea called America.'

One leads seamlessly into Ol' Man River and Bono wishes God's blessing on America as the band walk offstage to a thunderous reception. For the second time in a few days we get the mighty threesome of Discotheque, The Fly and With Or Without You and before we know it, out of nowhere comes The First Time.

'I have a lover, a lover like no other
She got soul, soul, soul, sweet soul
And she teach me how to sing
Shows me colours when there's none to see
Gives me hope when I can't believe...'

This is the first time the band have performed this wonderful song since Dublin in 1993 at the RDS Arena - and it felt so fresh. And the night ended with Bad... (what more is there to say ?)