Getting a pop star to play at your birthday party is an old trick for multimillionaires these days - but few people could get an orchestra to entertain their guests.
However, as patron of the Philharmonia Orchestra, Prince Charles was presumably able to call in few favours, and celebrated his birthday with a Wagner concert at Buckingham Palace, with the event costing a cool $800,000 according to reports.
According to a report in The Telegraph today, the bill for the event last week was paid for by Cyrus Vandrevala, an Indian private equity tycoon and philanthropist, and his wife, Priya.
A spokesperson for the Prince told the Royalist that the concert was to celebrate the Prince's patronage of the orchestra, Wagner's 200th anniversary and that it wa just happy good luck that it coincided with his birthday.
They would not be drawn on the cost. Or who paid it.