There are many kinds of random generators for games, but last night I found one that seems to be unique.
It is a music generator. To be more precise, it is a minuet generator.
The code on this page is based on the a game purported to have been created by Mozart used to create a minuet. It adds more features like a score generator and a midi file. Although you can play the results on the webpage, a good midi patch opens the possibility to expand into string instruments and beyond.
Its usefulness isn't limited to just playing music. Use the aforementioned score generator, add some 18th century script, print it on yellowed paper and you have a good prop. You could use the plot of The Purloined Letter, but change the letter to a mythical Mozart's Lost Score.
Take a listen to some of the compositions. It will sound better than you think.