Prior to his graduate work, Zielke received a B.M.E. from Friends University (Wichita, Kans.) and taught middle and high school choral music in the Kansas public schools. Following his graduate work, Zielke was the Associate Director of Choirs at the University of Arizona where he conducted the Symphonic Choir and worked as a colleague with the late Dr. Maurice Skones.
Zielke is a frequent clinician and guest conductor, including the Academic Orchestra of the University of Stuttgart and the University of Tübingen Chamber Singers in Tübingen, Germany, as well as leading master classes and conducting at the Sichuan Conservatory of Music in Sichuan Province, China. Choirs under his direction have appeared at state, regional, and national conferences, including an invited 2015 performance at the National Collegiate Choral Association. In addition, Zielke is often invited to present workshops and lectures on choral music and music education, including a session on community singing at the 2017 National ACDA conference in Minneapolis.
Zielke is a past-president of the Oregon chapter of the American Choral Directors Association and a past-president of the Oregon Music Educators Association. Additionally, he currently serves as the Adjudication Chair for Oregon ACDA. He is also the founder and music director of the Corvallis Repertory Singers, a semi-professional ensemble devoted to exemplary performances of the finest in choral literature. Additionally, he serves as the director of music at the First Congregational United Church of Christ in Corvallis and is proud to be the voice of the OSU Marching Band.