In this article, a teaching artist shares their understandings about designing a large-scale interactive intermedial arts experience for children aged five to eight years, and articulates findings about the conditions that promote quality experiences of this kind. When designing interactive arts experiences, a tension exists between providing openness and structure that derives from motivations to inspire creativity, but this does not need to be the case. Fears of constricting and stifling participants' creativity are voiced frequently. Enabling constraints are presented here as a method of promoting openness, creativity, and acts of imagination in interactive arts experiences.