In 1994, he joined the Canadian Forces Reserves as a member of the Band of the Ceremonial Guard. In September 1997, he transferred to the Regular Force and was posted to the Royal Canadian Artillery (RCA) Band in Edmonton, Alberta. He enjoyed great success as a euphonium soloist with the RCA Band, which culminated in him being featured on three CD recordings with the band. In 2007, he released a solo CD with Janet Scott, piano on the Canadian Classical Label Arktos entitled EUPHONIUM. His recording has been featured on CBC Radio and also received acclaim from Dr. Philip Wilby in an article published in the British Bandsman entitled "Selling the Dream – Solo Recordings, Exams and Memorable Auditions". The British Bandsman is the oldest, continuously running publication in Britain.
In 2003, he was promoted to the rank of Warrant Officer and on completion of the QL7 Conducting Course in 2007, was posted to the Directorate of History and Heritage – Music in Ottawa. In 2008, he accepted his commission and was promoted to the rank of Lieutenant (Army Music Officer). For the next two years, he studied conducting and wind ensemble repertoire extensively with Dr. Gillian MacKay, Director of Wind Conducting at the University of Toronto. He also worked with other wind ensemble conductors including Professors Eugene Corporon, Dennis Fisher, Jack Stamp, Craig Kirchhoff, and John Whitwell. During this time, he also completed the Logistics Officer Common Course.
In 2009, he was posted to the Music Training Cadre, Canadian Forces Base Borden, where he was responsible for conducting and training Primary Reserve musicians from across Canada. He was also responsible for the supervision and leadership development of all instrumental instructors at the Music Training Cadre.
In Sep 2011, Lt (N) Matthew Clark was posted to the Naden Band, transferred to the Royal Canadian Navy, and as of 3 Oct 2011, is appointed as 20th Director of Music for the Naden Band of the Royal Canadian Navy.