An Italian trio widely accepted as pioneers of psy-trance, although many of their tracks would be categorized as electronica or ambient. The three men (Max Lafranconi, Maurizio Begotti and Andrea Rizzo) have also released under at least two other names: Pleiadians and Crop Circles.
Their music has heavy ethnic influences, which is not so surprising considering their name. They are also known for their heavy use of percussions. As usual for a changing artist that doesn't stick to strictly one genre, "true fans" of Etnica say the new albums are crap and not "what it used to be." If you are looking for more pure psy-trance, check out Pleiadians.
Etnica is also featured on countless compilations which I'm not even going to try to list here.
Sources:
http://www.spiritzone.de/Artists/etnica_nitrox.html
http://www.psynew.org
http://astral.fio.samara.ru/artist/etnica/etnica.shtml