The concert in memory of Diana, Princess of Wales will be an "incredible" night of music, Prince William and Prince Harry have said.
The concert, at Wembley Stadium on Sunday, will commemorate their mother's life almost 10 years after she died.
The princes toured the stadium to oversee preparations for the event, which will feature stars such as Sir Elton John and Lily Allen.
More than 62,000 music fans are expected at the event.
Harry, 22, described the transformation of Wembley Stadium from a football venue to a music arena as "amazing".
Speaking at a press conference after watching singer Joss Stone and her band perform a 20-minute sound check William, 25, said: "We're really excited by it.
"You heard Joss Stone singing, it's pretty amazing, we're very lucky to have her and everybody else that's singing along - it's going to make the evening an incredible night."
Among the stars taking to the stage on Sunday, which would have been the princess's 46th birthday, are Rod Stewart, Natasha Bedingfield, James Morrison, and Take That.
The princes personally asked Sir Elton to play the song
The princes also hosted a special lunch where they met poorly children, who are being supported by the charity WellChild - of which Harry is patron - along with their parents and carers.
About 100 children joined the princes at Wembley on Saturday, where they also watched rehearsals for the show.
Sir Elton, 60, a friend of Diana's, provided one of the most moving moments at the princess's funeral in 1997 when he sang a new version of his hit Candle in the Wind.
After the performance he vowed never to play the song again but it is thought he will for Sunday's concert.
Harry, when asked by the BBC if the singer had helped with the planning of the event, replied: "He's helped massively just by saying yes, and obviously a personal request from us is to do Candle In The Wind again. So hopefully he'll be playing that."
The princes have also said they will get up on stage at some point during the concert.
Both BBC Radio 2 and BBC One will be broadcasting live from the event.