"OK GO" :

 

"Ok go" is an American music band of four men : Damian Kulash, Tim Nordwind, Andy Ross and Dan Konopka. They make Rock and Power Pop music. This band was created in  1998 and still play music today. They often use in their videos clips chat we call "the butterfly effect" : This is when one things pulls an other things without human actor.

Here is an example of their videos when you can see "the butterfly effect" : http://www.youtube.com/watch?v=qybUFnY7Y8w

I particularly like their last video: http://www.youtube.com/watch?v=MejbOFk7H6c

 

 

~ official site of "OK GO" here.