A man walks into a bar with a monkey on his shoulder. The bartender says, "Hey, you can't bring that monkey in here!"
The man replies, "Don't worry, he's well-trained. Watch this."
He then whispers something in the monkey's ear and the monkey jumps off his shoulder, runs over to the piano, and starts playing the most beautiful music the bar has ever heard. The bartender is so impressed, he gives the man a free drink.
As the night goes on, the man whispers more commands to the monkey, and it continues to impress everyone with its talents. Finally, the man stands up and says, "I have to go, but my monkey can stay and entertain you all."
The bartender, now curious, asks the man as he heads for the door, "How did you teach your monkey to play the piano like that?"
The man replies, "Oh, it's simple. I just told him to practice his scales."