This thesis examined music participation and non-participation by older adults in Queensland, Australia. It explored why relatively few older adults take up or resume playing a musical instrument despite the reported benefits of participation in community music ensembles. It also sought to better understand the constraints faced by active, older-adult musicians, and how these constraints could be overcome to fulfil music motivations. Specifically, the thesis sought to address the following research question: How can participation by older adults in community music instrumental ensembles be better facilitated in order to initiate, promote, and sustain appropriate, engaging, and dynamic music-making experiences? Over the past two decades, increasing attention has been given to global ageing, evoking UN and government reports that address this demographic transformation. In 2010, the Queensland Government’s strategy Positively Ageless was followed in 2011 by the Brisbane City Council’s program of activities for seniors Growing Older and Living Dangerously. In this program, sporting or other non-music activities appear to take priority over music activities even though participation in music making has shown to provide cognitive, physical, and social benefits that improve the quality of life of older adults. This mixed methods research began with an online survey that investigated the leisure choices of older adults and the perceived barriers to community music participation. Motivations for and constraints to music learning and engagement were then explored in interviews with older-adult musicians from music ensembles in South East Queensland. Following this was a focus on the intrapersonal, structural, and interpersonal constraints to music participation. The research findings led to the development of the MASTER framework, which recommends that activities are made musical, attractive, social, timely, educational, and regulated. This framework is offered as a way to better facilitate community music activities for older adults in Queensland, but it could be applied to other national and international participatory music settings. With increasing numbers of baby boomers now entering retirement, this research has implications for promoting healthy ageing, and for creating musically vibrant communities not only in Queensland but across geographic boundaries.