A tourist in Vienna is going through a graveyard and all of a sudden he hears music. No one is around, so he starts searching for the source. He finally locates the origin and finds it is coming from a grave with a headstone that reads "Ludwig van Beethoven, 1770-1827".
Then he realizes that the music is the Ninth Symphony, and it is being played backward! Puzzled, he leaves the graveyard and persuades a friend to return with him. By the time they arrive back at the grave, the music has changed.
This time it is the Seventh Symphony, but like the previous piece, it is being played backward. Curious, the men agree to consult a music scholar.
When they return with the expert, the Fifth Symphony is playing, again backward.
The expert notices that the symphonies are being played in the reverse order in which they were composed, the 9th, then the 7th, then the 5th. By the next day the word has spread and a crowd has gathered around the grave. They are all listening to the Third Symphony being played backward.
Just then the graveyard's caretaker ambles up to the group. Someone in the group asks him if he has an explanation for the music.
"I would have thought it was obvious," the caretaker says.