The band played it at their latest show in Las Vegas' Sphere
Bono also said it's "beyond the beyond of ‘tough’" playing without the drummer at their Las Vegas residency
The frontman also said he doesn't think "the world is waiting on the next U2 album”
Adele crafted a personalised message for Merchant, unlike the U2 frontman.
"I could’ve just pointed out the sexism and left it there"
Paul McCartney and Lady Gaga are also among the acts to have been considered
The band recently extended their Las Vegas residency due to "unprecedented demand"
The track from 1983's 'War' was the first to feature vocals from The Edge
She last joined the band on stage back in 2015
There is speculation about who will play at the venue once U2 finish their residency