“…Boundary artifacts refer to objects of practice that span boundaries between different social worlds (i.e., involved parties such as performers, composers, audience) or the boundary between the material and the virtual, while maintaining certain meaning in each case. For example, in distributed music lessons, it is often necessary to present a shared electronic music score to the remote participants, providing them with a shared context of reference and an additional interaction means for organizing distributed collaborative work [16], [17]. The music score may be designed so as to be sensible to the participants' local actions, in order to afford tracking and sharing contextual information in the course of a music performance.…”