Music self-efficacy has been acknowledged as a strong predictor of successful performance among musicians and music students, but is less researched among amateur musicians. The purpose of this study is to examine the connection between music self-efficacy and learning and playing habits of amateur musicians who had preferences for online music tutorials as an informal learning technique. Two hundred and twenty-two amateur musicians completed four research questionnaires: (a) a general background questionnaire including learning and playing habits, (b) music self-efficacy, (c) self-esteem, and (d) online music tutorials users' preferences, which distinguish between autonomy online music tutorials (fostering independent learners, incorporating context, and background) and dependent online music tutorials (offering mainly imitation options and providing little further knowledge). The results of the study supported the hypotheses, which predicted high music self-efficacy to be associated with the use of autonomy online music tutorials, co-playing, studying with a teacher, and self-esteem, and low music self-efficacy to be associated with the use of dependent online music tutorials. As music self-efficacy is crucial for students' learning processes, we argue that music educators could refer students to optimal use of online music tutorials, thus fostering autonomous learners. Further research is required for clarifying the impact of personal characteristics and playing habits among amateur musicians on their music self-efficacy.