"World Music" and "Global Hip-Hop"

I always thought the label "World Music" (at least in some of its applications) was a funny sort of arrogance/myopia.. as if Philadelphia decided that cheesesteak is the only thing normal people eat, and everything on earth that is not cheesesteak belongs to one secondary category known as "exotic food". Susana has a similar reaction both to that phrase and "Global Hip-Hop", and has sparked a nice discussion in her blog about the relative merits of the terms. Susana says:

In both cases it feels as though there's a grand division of sorts, where the Western world is placed in the centre of everything as an authentic norm, and the rest of the planet is lumped together as one uniform Other in juxtaposition. In the context of broader conversations on diversity, globalization, and multiculturalism in the West, this separation becomes more like a relationship of oppositions. The most vocal critics of multiculturalism cite how, too often, so many diverse and dynamic identities and expressions are reduced to either a single mass, or a series of static "tiles" (flowing from the metaphor of a cultural mosaic) held in place by a neutral mainstream. In either case, the normalized core culture (typically white, traditionally Western) is always the centrepiece and the measure by which all others are contextualized and discussed...

One difference that springs to mind for me is that unlike "music", "hip-hop" does describe a particular form that has a specific place and culture of origin, so phrasing that positions this place of origin as normative is not quite so absurd, though it may be debatable.

What do y'all think, about both or either? I think I have some questions, too, about David Dacks' response in the comments, but I need to go back and reread.