Despite many decades of academic interest in music and autism, we know little about what music means to autistic adults and how they experience it. The few existing studies lack a common theoretical basis and are therefore difficult to compare and integrate. To address this gap, we investigated whether Self-Determination Theory can be used as a common framework for understanding the functions of music as experienced by autistic adults. We focused specifically on the support and thwarting of the basic psychological needs (autonomy, competence, and relatedness). Thirteen autistic adults (seven women and six men; aged between 24 and 69years) described their experiences with musicking in a one-to-one semi-structured online interview. We analyzed the transcripts using directed qualitative content analysis (DQCA). We found that music engagement can thwart as well as support autonomy, competence, and relatedness and that Self-Determination Theory indeed offers a robust starting point for understanding the functions of music as seen by autistic adults. We illustrate how basic psychological needs provide a red thread connecting all previous studies that investigated the experience of music in autistic adults.