The 1 through 5 scale works... in an ideal internet. Personally I think a 1 to 3 scale would be better.
There's really no need for a luke warm in-between number. If you don't like or dislike, then why rate? And why numbers at all? Why so many too much thought. What's the point? Having taught classes, I hate grading. I'm not going to sit around pondering over a proper "grade," which itself is subject to the whims of the populous (where some view a 4 as "great but not perfect" and others view it as "you suck, but I'm being polite" ). It's meaningless.
If you want some way to gauge quality, a simple thumbs up vs. thumbs down (or like/dislike) would be effective. And less degrading for the artists too. The less values you have, the less "stinging" the lowest rating is. And if they aren't numbers, it feels less like a "grade" and more like personal opinion.
If nothing else, ratings should have an even number of responses (2 or 4 or 6 -- though more is worse, IMO). "Center" numbers are useless in a true (and voluntary) system. They mean "I didn't feel one way or the other about this." And if you don't care, why rate it at all?