Die Bremer Stadtmusikanten (Town Musicians of Bremen) is a fairy tale from the Brothers Grimm. 

I used to listed to this growing up as a kid. Here is a brief summary of the fairy tale. 

A donkey, dog, cat, and rooster were growing old and seemed useless to their masters. The four animals did not want to be thrown out, mistreated, or even worse, killed by their masters. One by one, the animals left their masters houses and ventured off to the city of Bremen in hopes of becoming musicians. 

Bremen was much to far to reach in a single day. During the night, the four animals saw a house with a light on. The house was occupied by robbers. The four animals put their heads together and decided to come up with a way to scare the robbers off, they made noises and successfully scared the robbers. The animals then ate what was on the table and rested in the house throughout the night. 

One robber returned to the house later in the night as ordered. The cat scratched the robber, the dog bit the robber on the leg, and the donkey kicked the robber while the rooster made terrifying noises. They believed the house was haunted and no one ever dared enter the house again. The animals never made it to Bremen because they liked the house so much that they would stay and they did happily ever after! 

Today, there is a bronze statue of the Town Musicians of Bremen next to the Rathaus.  Apparently, rubbing the nose of each animal on the statue is supposed to bring good luck. The statue is a very popular attraction in Bremen. Because of this, there is always a line of people waiting to rub the noses for good luck or do touristy things like take pictures with the Town Musicians of Bremen.