Bono has compared the new eXPERIENCE+iNNOCENCE U2 tour to method acting in a Marvel movie.
The Irish hitmakers kicked off the mammoth run of dates in Oklahoma last night, with Bono describing the shows as a big technical monster.
The iconic frontman later admitted onstage that rehearsals for the gigs had gone really shite.
Its sort of like doing a big Marvel movie, except youre taking this to a different city every few days so its a bit mad, he told The Irish Sun.
For me, its like a Marvel film where youve got to method act, so thats not right.
He added: Its a big technical monster but it has to have a big bloody heart inside of it, in the machine, and thats what we do. So it is an unusual way.
Despite the shaky preparations, the tour went ahead anyway and featured a touching tribute to Bonos late mother Iris. As he sang the chorus to I Will Follow, footage of his parents wedding day played on the big screen behind.
U2s trip stateside concludes in mid-July. Then the Dublin rockers head to Europe for gigs in Germany, Portugal, France and more.
Its all part of promotion for their new album Songs of Experience, released at the end of last year.
In an interview with Rolling Stone, Bono revealed that he almost died during the albums recording. But when quizzed about what happened, he refused to elaborate, instead responding: Well, I mean, I dont want to.
He added: Its one thing if you were talking about it in a place of record like Rolling Stone, but by the time it gets to your local tabloid it is just awful. It becomes the question that everyone is asking.
You can read details about U2s upcoming tour and buy tickets here.