It was a tense and nervous U2 who arrived in San Diego for tonight's first show of their Vertigo world tour.
"It really is nerve-wracking for them" said their manager, Paul McGuinness. "I think they're so nervous because there have been some great shows in the past and people have high expectations of what's going to happen on this tour."
The band have been rehearsing in Mexico and Canada over the last few weeks. They had full dress rehearsals in Los Angeles over the weekend in front of a select group of fan club members.
Speaking about the set list for the tour, McGuinness said the band would be leaning heavily on their current album, How To Dismantle An Atomic Bomb.
"They're very excited about the new material and want to avoid doing a greatest hits show.
"They are determined not to become their own kind of tribute band. It's about getting the balance right and accommodating the songs that people really expect to hear", he said.
The Vertigo tour is understood to feature the same type of scaled down stage production used in the band's last "Elevation" tour.
"It's different but similar," said McGuinness.
The band will tour around the US until May and begin the European leg of the tour in June. There is still no final word on whether the band will add a third Dublin date to the tour - the two Croke Park shows on June 24th and June 25th sold out within minutes.
It appears that one of the problems is that the band are rumoured to be playing the final night of the Glastonbury Festival on June 26th.
Just last month the band were inducted into the Rock and Roll Hall Of Fame at a ceremony in New York.
"It's very unusual, in fact, unique to be having a number one record and selling out a world tour while you've just been inducted into the Hall Of Fame," said McGuinness.
"That's normally reserved for venerable, rather older people." With current worldwide sales of the new album standing at nine million, it appears that How To Dismantle An Atomic Bomb is on course to become the band's biggest ever selling record.
They are closing in on the 15 million sales of their Joshua Tree album which was released in 1987.
There's a lot of excitement among fans who have travelled from around the world for tonight's first show at the San Diego Sports Arena.
Last night a number of "Vertigo Eve" parties were thrown in the city.
Tickets for tonight's sold-out show are reported to be changing hands for thousands of dollars.
The last U2 tour in 2001 saw them play to two million people and earned them €60 million.