Given that this Missouri city has such a strong tie to music (come on, even its hockey team is called The Blues) it makes total sense that the locals would embrace creativity. There were a ton of music instructors and stores, the third most art supply stores, and even the 11th most performing arts.
This was also an ideal place for learners. There were a whole bunch of colleges and universities, as well as a fair amount of art schools. On top of that, the eighth most bookstores populated this city with a wealth of creative knowledge.
All of this led to St. Louis having the ninth highest percent of the population in the arts and entertainment industry.