Farting in the bus

John took a bus to office one day.

In the bus, just while he was enjoying a fantastic music, he have an urge to fart, must be the onion ring he had just now. The bus was full of people, so he can not fart loudly....

While he listen to the music, he have an idea. He can synchronise his fart with the music beat, ya that was a great idea, he thought. So he just released his gas when the beat was loud.

But after a few round of farting, he noticed everybody were staring at him in a strange way.

Why? he thought, the music beat was covering the farting sound every time. What went wrong?
Then he look downward, and he noticed his MP3 player.

Ooooo.... ya the music came from his MP3 player to his EAR PHONE!