Abstract. This demo paper presents an interactive tabletop interface with tangible building blocks to engage business domain experts in process modelling. This interface, called Metasonic Touch, is a commercial product based on results of the European research project IANES (Interactive Acquisition, Negotiation and Enactment of Subject-Oriented Business Process Knowledge). BPM conference attendees will be able to use Metasonic Touch and experience the ease and playfulness with which it allows collaboratively modelling, understanding and discussing a process. The target audience includes BPM researchers and practitioners interested in agile and stakeholder-oriented approaches to process modelling. Keywords. Subject-oriented business process modelling, knowledge elicitation, tabletop interfaces 1 Significance to the BPM Field