Alongside these projects, Harper is the owner and founder of Takeover Live, a broadcasting and media production company that specializes in live-streaming bands along with giving artists a platform to share their sound on.
Harper Founded Yellowcard in 1997 with Longineu W. Parsons III, Ben Dobson, Todd Clary, Warren Cooke, and Sean Mackin after meeting at Douglas Anderson School of the Arts.
Shortly after the release of their EP, Todd Clary left the band, Key then filled in as the rhythm guitarist.
Billboard 200, the album was a commercial success in the United States with the hit singles Way Away, Ocean Avenue, and Only One.
In 2005, Harper went with the other band members to Los Angeles while Key and Mosely moved to New York City to create new material for their next album.
In an interview with MTV News, he said that he was finished with writing the guitar tracks for the album and that he was leaving the band.
After leaving Yellowcard, Harper joined Amber Pacific as their rhythm guitarist, replacing Justin Westcott.
[2] In 2008, Harper joined the band as the new lead guitarist alongside Steven Neufeld, Justin Cabrera, and T.J Arriaga.