Matthew Kocmieroski is the principal percussionist with the Pacific Northwest Ballet Orchestra. He also regularly performs with the Seattle Symphony and Seattle Opera orchestra.

In addition to his orchestral work, Kocmiersoki maintains an active schedule as a chamber musician. He co-founded and was artistic director and percussionist for the New Performance Group, as well as a principal member of Taneko. He also co-founded and is a principal member of the Pacific Rims Percussion Quartet. He regularly performs with the Seattle Chamber Players, and has appeared at the Seattle Chamber Music Society Festivals, the Icicle Creek Music Festival, the Marrowstone Music Festival, the Methow Music Festival, the Orcas Island Chamber Music Festival, the Seattle International Chamber Music Festival, and the Bellingham Festival of Music. Internationally he has appeared at the Bergen, Moscow Autumn, Moscow Cold Alternativa, St. Petersburgís Sound Waves, Kiev MusicFest and Warsaw Autumn festivals.

Kocmieroski takes great pride in his work collaborating with numerous composers, both established as well as emerging, on the development and premiere of important new works and the recordings that have resulted from these collaborations. Kocmieroski may also be heard on a variety of solo, chamber, and orchestral music recordings as well as on numerous major and independent motion picture, television, and video game soundtracks.