This text presents an approach to motion estimation for musical applications using ultrasonic technology and low-cost, off-the-shelf components. The system can estimate motion in volumes ranging from very small to room-scale, with precision varying from sub-centimeter to millimeter accuracy, depending on the conditions. Three case studies are discussed, highlighting the versatility of the approach and exploring its range of applications, and the common technical details of the underlying system is presented with an encouragement for further work in with musical application of ultrasonic motion estimation in general and using larger capture volumes in particular.