Although drummer and founding member Larry Mullen Jr. will not take part in U2's performances at the Sphere in Los Angeles for health reasons - Bram van den Berg will take his place at the concerts - was found with the other three in the tow truck that was rolling around the city, having apparently taken part and in the recording made earlier for 'Atomic City'.

The band also performed an improvised acoustic version of 'I Still Haven't Found What I'm Looking For', recalling a moment from the video in Las Vegas in 1987

Their relationship with Las Vegas goes back years
U2 will kick off their Sphere Las Vegas show with at least one new song: "Atomic City," a Las Vegas-themed track that's expected to be released on or before the band's opening night on Sept. 29. While filming a music video, the foursome played the song repeatedly while perched on a flatbed trailer parked on Fremont Street in the neon-filled downtown.

The website U2songs.com immediately collected comments and reports from fans who recorded video of the shooting in downtown Las Vegas, posting the full lyrics to the song as well as video clips of Bono's performances and comments. Las Vegas Review Journal entertainment columnist John Katsilometes was also in attendance and provided plenty of footage from the shoot as well as a print report.

"He doesn't listen to doctors' orders"
"The four of us recorded the song. Unfortunately, Larry Mullen Jr. he won't be with us at the Sphere,” Bono told the audience, Katsilometes reports in the Review Journal. "He doesn't listen to doctors' orders... Neither do many of us. But he's here tonight… Give Larry Mullen Jr. a round of applause.”

The arrival of the truck pulling the trailer downtown was not a spontaneous event. Two hundred and fifty collaborators were solicited by email and paid $150 each for the shoot, during which the band sang "Atomic City" four times.

Apparently no cell phone ban was imposed on the extras, as almost every observer on set seems to be holding one to take video. Fans at the venue told U2songs.com that the backing tracks during the shoot appeared to be pre-recorded, but Bono was singing live.

Like old times
Bono described the new song as "a rock 'n' roll 45 in the tradition of '70s post-punk, Blondie, the Clash... We've circled it all over."

The title of the new song refers to a nickname that Las Vegas got in the 1940s.

“I’m free / I came here for the fight / I’m front row in Las Vegas / And there’s a big one on tonight” go the top lines on the Sin City-centric song.

"It's like Saturday night, Sunday morning"
The band also entertained them by playing - not on a backing track - a new cover of 'I Still Haven't Found What I'm Looking For', the original video for which was also shot in the same area of downtown Las Vegas at the end of the decade of 1980, before the current outdoor roof was installed over the famous boulevard.

Bono told the crowd they were reworking the 1987 rock classic, saying: “Let's try it as a country song. So anyway it's something like Saturday night, Sunday morning - it's a confession about not going to confession."

According to U2songs.com, Mullen recorded with the rest of the band in the south of France as well as in two Los Angeles studios with producer Steve Lillywhite in sessions that wrapped up early last week. The website noted, however, that Bono appeared to be improvising or scanning at points, indicating that the lyrics may sound altered.

The fan site noted that this was the band's first public appearance since completing 'Joshua Tree' in late 2019.