First, taste, as illustrated in two music videos. Do yourself a favor and watch both. Watch both the whole way through, it's very much worth it and I think they will illuminate much of my thinking on the topic of the blog post.
1. Akron/Family "Silly Bears"
2. Scott Walker/Sunn O))) "Brando"
Both of these are classified under "Experimental Rock" and I enjoy the hell out of them both. But, there is a huge difference in tone and they illustrate much of how I've been thinking about running RPGs late.
Make sure you've watch both and then continue reading.