There’s more than one Companion.

1) A rock band from Brooklyn started in 2012 with Pepi Ginsberg, Anna Thorngate, Tim Lappin, Kirk Schoenherr, Amy Carrigan and Kyle Olson. https://www.facebook.com/Companionmusic

2) A pop rock band from Dallas, Texas consisting of Alex Dean on lead vocals and guitar, Shawn Spurrier on drums, and Chase Studdard on Guitar and backup Vocals. Their MySpace is provided below:
http://www.myspace.com/wearecompanion

3) A Hardcore/Death metal band from Aroma Park, Illinois.
http://www.myspace.com/hailtoupee

4) A progressive rock band from United States, with strong connections to Leviathan (another US progressive rock group). Their only record was Reap the Lost Dreamers (1974).

5) A Screamo/Emotional Hardcore band from Southwest Missouri founded in 2011.