For a rather otherworldly musical experience, I would recommend checking out one of the discs that document Tod Dockstader's experiments with electronics and tape loops, all of which were composed in the early to mid-'60's. When you consider the sounds and sonic explorations that this man created with what would now be considered the most rudimentary recording & editing technology, it really is fairly befuddling. On some levels, it puts much modern electronic music to shame and it is much more compelling than some similar minded music that was being created at the time, which became a little dry and academic. There's at least 2 CD's out and I'd recommed the one called "Apocalypse" with his classic 'Luna Park' composition.
For modern examples of similar strange-ness, try anything by Biota; a group of folks from Colorado who create some seriously unusual sonic-soup using mostly processed acoustic instruments. Their recordings are accompanied by artwork created by the band as visual interpretations for the music therein. Not for everyone, but a unique experience nonetheless.
