Dog playing piano

It is World Piano Day!

A man walks into a bar with a small dog under his arm and sits down at the counter, placing the dog on the stool next to him. The bartender says, "Sorry, pal. No dogs allowed."
The man says, "But this is a special dog – he plays the piano!"
The bartender replies, "Well, if he can play that piano, you both can stay... and have a drink on the house!"
So the man puts the dog on the piano stool, and the dog starts playing. Ragtime, Mozart... and then he plays some rock 'n' roll. The bartender and patrons are amazed.
Suddenly, a bigger dog runs in, grabs the small dog by the scruff of the neck, and drags him out. The bartender asks the man, "What was that all about?"
The man replies, "Oh, that was his mother. She wanted him to be a doctor."