Barnyard Bunk (1932)

An old farmer has let his entire farm go and it is falling down around him, with mice taking over. Tom and Jerry (the human versions, not the cat and mouse) show up with magical saxophones, and the music has amazing effects on the farm. A chicken lays dozens of eggs, a cow gives gallons and gallons and gallons of milk, and two woodpeckers don't just peck a tree, they cut it down and split it into firewood. Even the farmer's well changes, filling with beer (by the mug of course) instead of water. The farmer trades Tom and Jerry a huge bag of money for the saxophones, but he gets the better deal - the bag is full of the mice from the start of the cartoon, and they carry Tom and Jerry off to throw them into the pond.