Glass and Fans are two participatory spatial sound installations created with the Spatial Infra-Instrument Framework (SIF), investigating how interactive interfaces like SIF can expand the scope of music-making to include collaborative, non-linear processes that can evolve with their artists, audiences, and the public over time. SIF utilises open-source tools such as openFrameworks and Kinect v1 to provide a low-cost and flexible framework that supports and encourages the education and artistic practice of building New Interfaces for Musical Expression (NIMEs). Each SIF iteration is a stand-alone structure and has two performance modes: (1) Machine mode, instrument performs as the composer has specified; (2) Human mode, instrument becomes interactive for audience. Glass takes a series of fragile, hand-blown glass percussion and provides access to their tonal and textural qualities. Machine Mode plays audio and visual samples as programmed by the composer, Human Mode invites audiences to compose within the same ecosystem through rear projection and set of spatial triggers. Fans translates the everyday material of computer fans into an infra-instrument. Machine mode performs with the "tuned" fans at set speeds and intervals. Human Mode allows audiences to compose with the electromagnetic field (EMF) microphones by changing their distance and position.