We present a soma design process of a digital musical instrument grounded in the designer's first-person perspective of practicing Dalcroze eurhythmics, a pedagogical approach to learning music through movement. Our goal is to design an instrument that invites musicians to experience music as movement. The designer engaged in the soma design process, by first sensitising her body through Dalcroze training. Subsequently, she articulated her bodily experiences into experiential design qualities that guided the making of the instrument. The process resulted in the design of a large suspended mobile played by touching it with bare skin. We shared our instrument with 7 professional musicians and observed how it inspires a variety of approaches to musical meaning-making, ranging from exploring sound, to choreographing the body. Finally, we discuss how engaging with Dalcroze eurhythmics can be generative to the design of music-movement interaction. CCS Concepts: • Human-centered computing → Interaction design process and methods.