[holden]

I think the term "progressive" is relative, since a lot of the bands that had that label in the 1970s eventually ceased to be progressive, not evolving and releasing the same stuff over and over, or else tainting the public's perception with ill-advised pop turns in the 80's (what wasn't ill-advised back then?!). Progressive usally means being on the forefront of music or a step ahead. i think this is UW's intent with the riverrun series.
i was and still am a huge fan of Genesis. Most Pink Floyd is enjoyable. But bands like Yes and ELP fell into that category of tiresome and repeating themselves. In the 90's, i guess everyone cites Radiohead as carying on the torch, along with Sigur Ros. But anyone who's into indie music will tell you that there are thousands of extremely creative bands that are truly progressing music. That's where i'd look for real experimentation.

holden