I don’t know if you’ve ever seen a routine by Bill Bailey where he looks at the influence of cockney music on the output of classical composers. If not, you can watch it on YouTube — it’s definitely worth seeing, particularly if you like classical music! (Plus, the rest of what I am about to say probably won’t make sense if you don’t watch it).
Anyway, he says that there is only one recorded instance in classical music where the cockney “Have a Banana” is used – in the opening bars of Grieg’s piano concerto. However, I believe I’ve found another: listen to the first few bars of Chopin’s Polonaise No. 3 in A Major (Op 40) — see if you can spot another ‘have a banana’… or several, in fact!
In other random humour, I found a good website today with humorous answers to tests, it had a few there which I hadn’t seen before.