Here's a link to a neat article by Nate Wolley, trumpeter, composer, improviser, writer, and organizer of websites, events and etc. It's a selection of his favorite "weirdo" composers - we might have called them "American experimentalists" at one point, but at this point, maybe the term "wierdos" will do just as well.
http://www.thewire.co.uk/in-writing/the-portal/nate-wooleys-guide-to-american-weirdos
It starts off with a link to Kenneth Gaburo's work, and at the end of that, there's a "see also" link through to me, David Dunn and Larry Polansky. A lovely article with a bunch of great YouTube links, and a bunch of "see alsos" to give you names of other folks whose music is well worth pursuing.