You may already know the story but this version, told in rollicking rhyme, is the best. If you've ever struggled to find words that rhyme, you'll be filled with admiration and envy for Robert Browning's ingenious word pairings. Some of them will be words you didn't even know existed - for years I've been suspicious about 'nuncheon' - but I've just googled it - and it's a real word.
The main message of the story is, of course, pay what you owe - but it's instructive in lots of other ways : make sure the people you've voted for do their job - don't fall for a nice tune - sometimes it's best to be at the back of the queue....