You know, I don't usually comment on stuff like this. I make comments inside my head, at best. Even then, it's mostly critique. Now, when I stumbled upon this icon, I literally almost shouted out load: "this is absolutely amazing!" It is, without a shadow of a doubt, absolutely brilliant. As far as I'm concerned, this might as well be selected as the official iTunes icon. It's quite significantly better than the current one. Yes, saying this might seem cliche and tired, but in this case, it absolutely rings true.
If you're using Windows. I found this method: "Hmm a suggestion would be is deleting it the icon from you desktop, and going to the itunes program files folder. Then right clicking the .exe and click copy- then pasting it as a "shortcut" then it might work I dunno thats what i've heard. So best of luck and get back if you have any luck with that!
Another user said it worked. So you can give it a try