The little pianist.
 

A guy walks into a bar with a decently large brief case and sets it on the counter.

The bartender asks the patron what is in the case. The patron says, "I'll show you" and opens the case, revealing a tiny piano and a man standing about 10 inches tall.

A small crowd had gathered around the guy and another patron asks if the tiny man can play the tiny piano. "Of course, he can play anything you would like to hear."

After several minutes go by, the astonished bartender asks where and how he came across such a treasure.

The patron says, "I found a weird lamp in an antique store and bought it. When I returned home I went about polishing it when suddenly a genie appeared! He told he I could have one wish..." At this point the bartender interupts the patron asking him what he wished for.

The patron replied, "Well, it sure wasn't a ten inch pianist."

seems funny and interesting, a nice one