Prince William & Kate Middleton's Secret Wedding Music Decisions

Christopher Warren-Green with Prince William and Kate Middleton inset

Getty; Inset: Mario Testino

Like most young couples, Prince William and Kate Middleton knew exactly what music they wanted at their wedding. But instead of an iPod or a deejay or even a wedding band, they've got the London Chamber Orchestra.

"The couple have very, very strong ideas of what they want," Christopher Warren-Green, the London Chamber Orchestra's music director and conductor for the occasion, tells PEOPLE. "And after all, at the end of the day, it is their wedding. It's a young couple's wedding, and they should have what they want."

Still, the pair did seek input from those closest to them. "They involved both sets of parents ? the Middleton family, as well as the Prince of Wales. And both myself and the organist and choirmaster of Westminster Abbey, of course, are here to advise and to help," Warren-Green says.

So, what can we expect from the music? "I'm terribly sorry," Warren-Green says. "Both Prince William and Catherine really want to try and keep things a surprise."

Warren-Green, 55, who's also music director of the Charlotte, N.C., Symphony, describes himself as "musically acquainted" with Prince Charles for 30 years, and is thrilled to see the young couple planning the rest of their lives together.

"Oh, they complement each other wonderfully," he says. "Prince William has all the great attributes of both his parents. And Catherine is one of the most intelligent, pleasant, bright, funny young women I've ever met. She's going to be a fantastic princess ? and an asset, not just to our country but to all the charities and patronages that I'm sure she will be involved in."

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