Gesture-based input devices for controlling music software should support expressivity. However, it is challenging to effectively design new gestural interactions that both exploit the capabilities of existing devices and afford user expressivity. To further the understanding of expressive interactions, we propose a demo that interactively supports users in the production of new gestural movements. Precisely, the demo implements an elicitation algorithm which rewards the originality of gesture dynamics to support users in the exploration of the space of motions they can perform. This demo is targeting 2D interactions supported by, for example, a mouse, trackpad or Sensel device. As users interact with their input device, movement dynamics (e.g. speed profile and orientation derivative) are computed and 2D strokes are segmented into small primitives. The originality of a new segment is then measured as the minimum distance to previously observed segments and fed back to the users as an audio cue; the greater the distance, the louder the feedback. Such sonification scheme encourages users to produce new behaviours. This elicitation produces a map of motion primitives wherein clusters identify prototypical user behaviour. The properties of these clusters, such as user specificity or time of invention, could be used to reflect on the user practice and identify new opportunities for interface design.