Jjamz was started at karaoke night at Guys in Hollywood. The band name is an acronym using the first letter of each member's name. The group was a means of escape from each member's respective bands at a time when things seemed hectic for each member. "Jjamz started at an interesting time in all of our lives. We all needed some kind of escape from relationships or our other bands. It was a tumultuous time, and the lyrics just came out. It was like word vomit. I can't remember," said Z Berg,lead vocalist for the Like, in one of their first interviews as a band.
The band played their first concert at the Echo Plex on January 27, 2009 and went on to release their debut album, Suicide Pact, on July 10, 2012. To support this release, the band opened for The Hush Sound during a brief tour in October 2012.
The song "Heartbeat" was featured in a promotional video for an upcoming update for the social media site Myspace.
Following James Valentine's departure from the band, the name of the band has been changed to PHASES. In early 2015, the band signed with Warner Bros. Records and on May 12, 2015 released their first new music under their new name. "I'm In Love With My Life," "Betty Blue," and "Cooler" were all released on the same day, with a music video directed by Ethan Tobman for "I'm In Love With My Life" released simultaneously. "I'm In Love With My Life" was featured in The Sims 4 Perfect Patio's official launch trailer.