Personally I would prefer a colour (or color) coded system that showed functions like Announcements and date sensitive information, or US and ROW (because it is a US site first and formost).
The BS and Music separation works but I am always interested in a wide variety of things and colour coding allows us to scan and decide, whereas a system that hides sections would not be inclusive and Folk is epitomised by inclusivity. We are a broad church. The problem with sections is not as bad as a filter but colour is immediate. Background and font colour allows for combinatorial representation (and affords many shades (of opinion?). Maybe a <DIV> layer that can be shown when hovering over an "explanation" area/link.

It can be done even with links CSS and HTML tags allow for it in all browsers. We could still call them blickies because it would not affect thread look and feel, only the list of threads.

I know Max's philosophy is to not be too clever because there are many luddites out there with legacy equipment (And the dreaded IE7 that does thing differently because Bill Gates can). And a few webmeisters follow the same logic. We want to reach everyone we can. Inclusivity again!