I'm guessing that guy (I'm assuming he's a musician) is the one you're linking to and quoting. So we have relevance in there :P
Now, going for a square signature could work, but if you want it to look good, I'd recommend doing something like aligning the text as perfectly as possible with the picture. Dealing with font sizes and colours and all that. Would provide a much more pleasing piece for the eye, and of course it would make it seem much more "professional" in an instant.
As it is now, though, it's definitely not crap. It's perfectly fine for what it is. But there is plenty of room for improvement :D
5/10
(to the next poster; could you specify on which of the images in my signature shows up when you review it?
In case I need to fix something :P)