I put joke - A Musical Joke (in German: Ein musikalischer Spaß) K. 522 - one of Mozart's works. I'm willing to be wrong. Please could you explain jove.
I put JOVE. JOE (ordinary chap) with V (five). Jove is another word for Jupiter which was the theme of some Mozart's works. I can see that JOKE would work just as well though. Will be interesting to see what the correct answer is.
If you look in Chambers under "one", one of the definitions is actually joke - as in "have you heard the one about ...". Pretty weak I think but if it's in Chambers it's up for grabs by the setters. And yes Mozart's works have a K number.