"Laying down the blueprint of progressive-anarcho-agit-freakrock" Edgar Broughton Band was one of the best underground bands in the 1960's from the UK, even with its obvious Don Van Vliet's inflected Beefheartian vocals and Hendrix-esque guitar eruptions (ala "Love in the Rain") check it out...
http://www.youtube.com/watch?v=wGTUUDVpNms