A guy walks into a bar and is stood quite happily drinking his beer when this other guy walks up to him and says \" in two minutes you will break wind and the first four notes will be that of the 1812 overture\". Sure enough two minutes later the guy farts and it is the exact fist four notes of Beethovens 1812. A friend of the guy who farted walks in and is quickly told the story. \" I dont beleive a word youre saying\" he says. \"Ok then\" he says \"hang on a minute\" and goes over to the other guy. \"Excuse me, but do you think you could chat to my friend?\" So the guy goes over and starts up a conversation. \" Oh by the way\" he says.\" in one and a half minutes you will break wind and the first five notes will be those of Cliff Richards song \"Summer holiday\". Sure enough one and a half minutes later he farts the first five notes of the Cliff classic. They both walk over to the guy and say \"how on earth did you know that (a) we were going to fart when we did and (b) what music it would be\"? The guy replied \" oh its easy. You see I\'m a fartune teller\".