Thanks for an interesting question!
As a native New Yorker, I proclaim(!) that Seattle is actually a cosmopolitan city with strong cultural influences from the six continents. Australia, Asia, Africa, Europe, South America and North American culture is well-represented here: music, food, art, theater, sport, and more.
Seattle isn't really a "capital" of anything in particular, it is simply a place where there is a lot of first-rate, rocking "stuff" to eat, see, do, and play.