Developing the Tudor Catch, another hundred years later Purcell took it further into Catch rounds which were in and of themselves quite innocuous. But when the music was added, pauses in the parts aligned with the lead lines to produce an obscene result as the melody line switched leads. Now, I'm not suggesting you do something that extreme, but the idea might really work for kids if it's just a tad naughty.

And for those of you looking for the music-hall monologues, they're almost all here.