We present a long-term collaboration between dancers and designers, centred around the transmission of the century-old repertoire of modern dance pioneer Isadora Duncan. We engaged in a co-design process with a Duncanian dancer consisting of conversations and participation in her transmission of Duncan's choreographies and technique. We then articulated experiential qualities central to Duncan's repertoire and used them to guide the design of the probes, the sounding scarfs. Our probes sonify dancers' movements using temporal sensors embedded in the fabric of the scarfs, with the goal of evoking Duncan's work and legacy. We shared the probes with our Duncan dance community and found that they deepen the dancers' engagement with the repertoire. Finally, we discuss how co-designing with slowness and humility were key to the dialogue created between the practitioners, allowing for seamless integration of design research and dance practice. CCS Concepts: • Human-centered computing → Interaction design process and methods.