Unsurprising to find that such a small percentage of applications were for musicians / singers. Is that not what the artist category in the O visa was designed for?
The O visa is only for people who can demonstrate "extraordinary" capability. This usually means published, well-known, etc. Not all artists and musicians qualify.
My father got the O visa after being on investor visa for some years. He said it was the fastest way to the green card but quite expensive in legal fees.
While he has a couple of patents, the crucial thing was the business notability for which lawyers recommended getting testimonials from upper management in publicly known companies such as Apple and Dell instead of lesser known industry specific companies.