In this study, we investigated the factors affecting the motivation of studio-based instrumental learners in Hong Kong. We interviewed a total of 13 participants who learnt the violin and/or the piano. We analyzed the interview data by selective coding accordingly to the three basic needs in the conceptual framework of Basic Psychology Needs Theory, which is one of the mini-theories from Self-Determination Theory. The thematization of basic needs are (1) autonomy, (2) relatedness, and (3) competency. We found relatedness and competence were more related to our participants. This study contributes to the understanding of studio-based, learning-environment characteristics as well as specific motivation factors attributed to the distinctions between the violin and the piano learning environments in Hong Kong. We also discussed the issues of music learning in school and teacher's style of teaching practice.