A lengthy steel rod spans above head-height and pivots on sturdy steel tripod legs. Each end of the rod holds an organically shaped handle with a speaker embedded. In fluorescent yellow, these handles invite passers-by to interact and play. With a slight nudge the top element would rotate and swing, and a gyroscope at the center translates this motion into a set of synth chords, accentuated with vibrato.
The gyroscope tracks both the change in rotation, as well as the acceleration along a particular axis. The change in rotation above a certain threshold changes the chord sets, whilst the acceleration controls the strength of vibrato.