Hm I'm curious, it looks really cool but it doesn't play for me. Do I need to hold the keys down? Maybe its my headphone. Google always steps up their game though with new cool Logos, they had a really nice animation a week or so ago.
The strings of the guitar can also be controlled by your keyboard, did you try that ? It's very addicting lol
Those of you with problems with the logo, you are probably using IE. IE is not a modern browser and this is further evidence of this. No one should ever use IE. It holds back the modern web.