Princess Michael of Kent has revealed that she once joined singer Peggy Lee for an impromptu rendition of her famous song Fever.
Marie-Christine, who is known for her indomitable character, talked about her passion for singing during a radio interview being broadcast tomorrow.
She told the BBC Radio 4 programme Saturday Live that she sings in the bath, likes Joan Baez and Joni Mitchell songs, and discovered karaoke when she attended a royal wedding in Malaysia.
She told presenter JP Devlin: "I sort of croon. Quite often at parties - small, private dinner parties - and somebody sits down at the piano and one sort of croons away. I even sang with Peggy Lee once - can you imagine?"
She explained: "Well, I was in New York and there was Peggy Lee, who has always been a great heroine of mine.
"I said 'You know, I've always loved singing your song Fever', and so she said 'Let's do it', and there was a piano and there was a pianist and so we sang together Fever - it was such fun, I can't tell you."
The Princess revealed that she has perfect pitch - the ability to identify any musical note - and, while her husband likes Abba, she loved hearing jazz during a visit to New Orleans.
Speaking about being introduced to karaoke, she said: "Well, I found it for the first time in my life in, of all places, Malaysia where we went for the wedding of the then king's daughter.
"They said 'Oh, we're having a karaoke evening tonight', so I didn't know what that was, so fine, yes, I thought it was some sort of marvellous food really and everybody was singing away and they sounded good, so that was quite fun."
When the presenter asked the Princess if she would sing for him, she joked that she had been told not to.
She said: "Well, because I've been told categorically that the press reaction will be that my next stop is the X-Factor, and I've been forbidden, forbidden. So there we are."
:: Saturday Live will be broadcast on BBC Radio 4 at 9am tomorrow.