Matthew Arnold Thiessen is a Canadian-American musician, singer and songwriter best known as the band's co-founder, lead vocalist, guitarist, pianist, and lead musician. rock Christian Relient K. With Relient K, he released 8 full-time albums, including 3 Gold Certified and 3 Top 20 on the Billboard 200. In addition to his work with Relient K, Thiessen also led a stint. The side project, Matthew Thiessen and the Earthquakes, released their debut album Wind Up Bird on August 31, 2018. In 2009, he co-produced and collaborated on Owl City's Ocean Eyes album.

Relient K's frontman is a vocalist and musician who specializes in alternative rock. He's also worked on projects like Owl City as a producer.