Ser are two different projects.. First one is instrumental rock band from Argentina. They also make some good Astor Piazzolla's covers.

http://www.ser-rock.com.ar

Second one is a experimental ambient darkwave post-rock/post-black metal project from Mexico/USA.

https://sermusic.bandcamp.com Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.