There are multiple artists named Simulacra:

1) Simulacra is a dark ambient / industrial solo project from Denderleeuw, Belgium, founded by Miguel Boriau in 2006. He composes a minimalist form of dark ambient, that emanates with hypnotic attraction. Miguel is also the owner of the label NOTHingness REcords, and founder of the projects Beyond Infinity, Insomnia, Mannus, and the neofolk duo Weihan.
Bandcamp: http://simulacra.bandcamp.com
Facebook: https://www.facebook.com/simulacravoid

2) Simulacra is a progressive metal band from San Francisco, United States, founded by Aaron Novik. Their style, consisting of only amplified and distorted clarinets, drums, and vocals, could be described as "clarinet metal".
Inspired by the "heavy chamber music" of Edmund Welles, Aaron invited Cornelius Boots, to start a more "traditional" rock format, with Cornelius playing the role of the bass player on an amplified bass clarinet and Aaron playing the role of the guitarist on an amplified and distorted B flat clarinet. The group is rounded out with singer Jesse Quattro (vocalist of Secret Chiefs 3 and Hammers of Misfortune), and Matthias Bossi (drummer of Sleepytime Gorilla Museum).
Their self-titled album was released ni 2008. It may sound like there are guitars and basses and keyboards on this record, but these sounds were all created by using clarinets played through guitar and bass effects and amplifiers.

3) Simulacra was a technical thrash metal band from Argos, Peloponnese, Greece, founded in 1997. They released only one demo in 2000, titled "...Towards Rapture?". Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.