This paper investigates the process of appropriation in digital musical instrument performance, examining the effect of instrument complexity on the emergence of personal playing styles. Ten musicians of varying background were given a deliberately constrained musical instrument, a wooden cube containing a touch/force sensor, speaker and embedded computer. Each cube was identical in construction, but half the instruments were configured for two degrees of freedom while the other half allowed only a single degree. Each musician practiced at home and presented two performances, in which their techniques and reactions were assessed through video, sensor data logs, questionnaires and interviews. Results show that the addition of a second degree of freedom had the counterintuitive effect of reducing the exploration of the instrument's affordances; this suggested the presence of a dominant constraint in one of the two configurations which strongly differentiated the process of appropriation across the two groups of participants.