It was the kind of thing jesters in the courts of the Plantagenet kings would have just about got away with – standing on stage with a bearded bard from Bath in front of the Prince of Wales and singing raucously about the royal family.
But Robin Williams, the comic actor whose death has shocked the movie-loving world, pulled it off with aplomb – even though the appearance with Bill Bailey at the 2008 celebration of Prince Charles' 60th birthday party was his first stage appearance in the UK for 25 years.
Yesterday, Keynsham-born comedian Bailey reflected on working with Robin Williams – the pair were put together by the organisers of We Are Most Amused and told to come up with a song to sing to the Prince, knowing that his family would be sitting around him.
The comedian admitted to being a bit awe-struck, and discovered that Williams' manic talent was matched by an incredible warmth.
"I'll remember him as a superb comic, a unique comedian in many ways," he said yesterday.
"He was quite a physical comic, he was very sharp, he had some brilliant material, some very topical, satirical stuff. There was a tremendous warmth you got from him."
Bailey and Williams' song was one of the highlights of the comic night, which pulled in millions of TV viewers when it was broadcast later. While the words were irreverent, the physical display of Robin Williams singing the blues was a stand-out performance.
"It's very sad news about Robin Williams – a brilliant comic and actor, a lightning quick improviser, a unique talent," Bailey tweeted yesterday.
Fellow British comedians also lined up to pay tribute to the man who, from across the Atlantic, had such an influence on their own careers.
X Factor judge David Walliams said he had the ''huge pleasure'' of spending time with Williams in Los Angeles with fellow Little Britain star Matt Lucas. He said on Twitter: "I was so in awe of him but he was so sweet and humble. We saw Robin Williams perform unannounced at comedy clubs in LA. His talent was breathtaking. Never seen such love from an audience."
Family Guy creator Seth MacFarlane said: "The world just got a lot less funny. Robin Williams is a tragic loss."
Gloucestershire comedian Simon Pegg called him a "true great", posting a YouTube link to a scene from Good Will Hunting.
Stephen Fry said: "Devastating news about Robin Williams – knew him a little and liked him a whole lot more. A brain wired like no other and so so kind."
And Rory Bremner said: "Really saddened to hear Robin Williams has died. He was a Catherine wheel of comic energy – brilliant, irrepressible, inspired. A true genius. His imagination was like electricity – flowed through him, lit him up, sparked wildly, consumed him. He inspired my generation."