Hard to search for this, so apologies if it has already been posted - but then again, KITTEH!!
The kitteh is cute but the music editing (which I think is the point of the video) is very good indeed.
That is some clever editing, which transcends the genre of animals doing stupid/cute things. 
Amazing talent to be able to “see” the music needed.
There was some mighty impressive tail puffage in that clip, too.
I’ll see your kitten v tennis ball and raise you The Sick Kitten (1903) ;). LOLkitteh from the dawn of (moving media) time!
Adorable 
I love how the kitten just sort of randomly spazzes out.
Cats is weird but kittens is hilarious.
Yes, the music was awesome, too, much better than the overloud random sappy music that usually accompanies these things.