Matthew Arnold Thiessen (born August 12, 1980) is a Canadian-American musician, singer, songwriter, and record producer known for being co-founder, lead singer, guitarist, pianist, and primary songwriter for the Christian rock band Relient K. With Relient K, he has released eight full-length albums, including three that were certified Gold, and three that peaked in the top twenty on the Billboard 200. Outside of his work with Relient K, Thiessen leads a side project called Matthew Thiessen and the Earthquakes, which released its debut album Wind Up Bird on August 31, 2018. In 2009, he co-produced and collaborated on Owl City's album Ocean Eyes. Musical career Relient K Thiessen founded Relient K in 1998, with guitarist Matt Hoopes, and bassist Brian Pittman, and recorded the demo All Work & No Play the same year. The recording attracted the interest of Toby McKeehan who signed the band to his label Gotee Records. Between the years 2000 and 2003, Gotee released three full-length albums, one Christmas album, and four EPs with Relient K. In 2004, their fourth album Mmhmm was released on both Capitol Records and Gotee, and peaked at number fifteen on the Billboard 200. After recording another EP in 2005, Mmhmm and Two Lefts Don't Make a Right...but Three Do, their 2003 album, were certified gold, followed by their 2001 album The Anatomy of the Tongue in Cheek in 2006. In 2007, Gotee, Capitol, and EMI released Relient K's fifth studio album, Five Score and Seven Years Ago, which peaked at number six on the Billboard 200. After the release of the double EP The Bird and the Bee Sides in 2008, the band signed with Gotee's Mono Vs. Stereo imprint, on which they released their sixth studio album, Forget and Not Slow Down, again reaching the top twenty of the Billboard 200. Thiessen and the other members of Relient K have taken up A&R positions for the label as part of the record deal. Thiessen has been the lead vocalist, frontman, guitarist, primary songwriter, and, along with guitarist/backing vocalist Matt Hoopes, the only member who has been in the band for its entire history. Because of this position of musical leader, he maintains the most creative and artistic control of the band members. He has also served as co-producer on several occasions as well. As the band matured musically, Thiessen started being credited with piano in most releases, beginning with