Duinker has maintained a side interest in composition and arranging throughout his life. Focusing mainly on works for choir or percussion, his compositions and arrangements have been performed Canada-wide by ensembles such as Architek Percussion, (Insert TITLE) Marimba Duo, TorQ Percussion, Canadian Chamber Choir, Camerata XARA, and various other choirs. In 2016/2017, Duinker's work "Four Lines" was toured across Eastern Canada by Architek Percussion.