Modular Organ is an assembled sculpture that is tactilely activated by the artist in performances. A pump blows air into a system of rubber tubes, organ pipes, and 3D printed, bird-shaped water flutes. The word organ carries a double meaning, as it also brings to mind the inner workings of a body. Performances include the dismantling of the kit-like structure into separate bits. Its transportability distinguishes the instrument from a traditional pipe organ, which is permanently embedded as part of the architecture. It has no claviature, and each individual pipe can be manipulated microtonally. In this way, the sculpture manifests instrument building as a mode of composition. The piece further transforms the original premise of the pipe organ by maximizing its potential auditive output and gaining microtonal control over the system, as well as composing with acoustic phenomena such as binaural beating and difference tones.