The Telegraph reports that Prince Charles and his wife had an unusual sort of encounter with a musical instrument recently.
The Prince of Wales and the Duchess of Cornwall were left speechless and in tears by the sight - and sound - of a 'cat organ'.
They came across the unusual musical instrument during a visit to an ambitious eco-festival staged in London but were unprepared for the levels of laughter it induced.
The Prince often enjoys a joke when he meets members of the public but was left laughing uncontrollably by the performance by sound sculptor Henry Dagg, 54.
The musician played for the royal couple as they toured Charles's 12-day eco-garden party staged in the grounds of three adjoining historic houses - Clarence, Lancaster and Marlborough.
At first, Mr Dagg evoked polite laughter from Charles and Camilla with his rendition of A Nightingale Sang In Berkeley Square played on a saw with a bow.
But for the encore he brought out his 'cat organ', consisting of a row of 16 squeaky toy cats, and played Somewhere Over The Rainbow, the tune made famous by Judy Garland.
The Prince was left red-cheeked, in a fit of giggles and wiping away tears as the musician, dressed in a bow-tie and waistcoat, squeezed the animals.
Mr Dagg was unfazed about the reaction to the sound he described as a 'cat-cophony' and said: "It's nice to make Prince Charles giggle a bit."
There's more at the link. Here's a video report of the incident.
For those who'd like to hear the 'cat-cophony' more clearly, the BBC has a video clip filmed in a studio, where the piece is much more audible.