Despite the increasing number of students in music education graduate programmes, attrition rates suggest a lack of success in retaining and assisting them to the completion of their degree. Based on the expectancy-value theory, the aim of this study was to examine students' motivations (values and competence beliefs) and their complex interaction with the social system. A questionnaire was sent to students from three graduate programmes in Mexico (two traditional, one distance learning), which examined both personal and environmental factors that have enhanced or undermined students' motivational beliefs. The results show gender differences; female students place higher value on graduate school, while male students hold higher expectations of success. Factors affecting motivation positively included perceptions of career development and income increase; the requirement to pursue an academic qualification as a part of an existing job; and interest in research. Factors affecting motivation negatively included the economic impact of study, time constraints and insufficient support and communication coupled with high expectations from advisers. (Contains 7 tables and 1 note.)