Among the tunes expected to fill the palace Friday night: Abba, a reported favorite of Middleton's.
The queen will reportedly attend the dinner, then retire for the evening soon afterward. "She's already said she'll let the youngsters get on with it. And they will get on with it," Arbiter said.
Nicholl added that Prince William has argued that he is not the heir but the heir apparent, which gives him more room for new ideas. "So if he wants disco balls, if he wants Abba all night, who's going to argue?" she asked.
The plans, including the installation of those disco balls, has apparently raised the eyebrows of palace staff. Nicholl said she thinks the public will understand what the young couple is doing, even if it's non-traditional.
"Let's face it, when William is eventually king, there are not going to be opportunities like this. He has this chance now, and I don't think anyone would begrudge him," Nicholl said.
Meanwhile, the queen and Prince Philip will be heading to Windsor Castle for the night, leaving the newlyweds and their friends to party all night.
"I think the fact that her majesty the queen is prepared to leave the palace for one night, and one night only, says that it also has her blessing," Nicholl said.
Even if the queen changes her mind and decides to stay at Buckingham Palace Friday night, Arbiter said, she won't have a problem falling asleep. A distance equal to an entire city block separates her bedroom from the palace's ballroom where the party will take place.
The party is by invitation only and no press will be allowed.