The practices and techniques of learning and teaching a musical instrument are highly tradition-driven. Therefore, the use of technology - hardware or software - is often strictly limited to certain instances of students' or teachers' practices. Despite technological progress and its application across numerous educational fields, instrumental learning has not yet harvested the full potential of these advancements. To fill this gap, the TELMI (Technology Enhanced Learning of Musical Instrument Performance) project aims to develop a complete technology-enhanced solution for violin learning and teaching. A distinctive feature of the TELMI approach is the application of Co-creation techniques to the design of the learning solution. Co-creation is "an act of collective creativity, shared by two or more people". Building on Living Lab and Co-design principles, the customized TELMI Co-creation approach involves end-users and domain experts - violin students and teachers - in the design process, allowing them to create their own solution. In this paper, we'll elaborate on the collaborative Co-creation methods that have been applied thus far in the project, including storyboards, personas, timelines, scenarios, and problem definition. In particular, guidelines and lessons from a series of interviews and workshops carried out with violin students and teachers will be introduced. The main aim of these sessions was the in-depth exploration of the use of technology in instrumental learning, as well as the acceptance of specific gamification techniques.
