“The idea to host this event came from Ariana," Melvin Benn, of promoter Festival Republic, told Billboard.
"She was very traumatized after the attack, but it was very important to her to support the victims and show a level of defiance that stands up to this bloodlust and ambivalence toward innocent individuals and tells the terrorists that they are not going to stop us," he added.
He also told Variety that he didn't expect the singer to come back so soon after suspected suicide bomber Salman Abedi killed 22 people on May 22 at the end of one of her shows.
"For such a young woman to have the bravery to stand up and do that, I think every act should take notice. By coming back, not just to get on stage, but to get back on stage in the city where it’s happened. It’s inspiring,” he said.
Braun booked the acts -- as previously reported: Coldplay, Justin Bieber, Katy Perry, Miley Cyrus, Pharrell, Usher, Take That and Niall Horan, arranging it so that all the acts but Coldplay will be backed by Ariana's touring band.
Benn said he also had to convince the Manchester United soccer team to start a match an hour and a half early to accommodate the crowds at the concert venue which is near the stadium where the soccer team plays. Organizers also had to get BBC TV, Radio and the Capital Radio Networks in the U.K. to preempt their regular programming to carry the concert.
"It's a phenomenal commitment, especially from BBC TV," which will air the entire show, Benn told Billboard.
After the attack, Grande suspended her tour but will resume it next month, following the benefit concert.