Purpose:For older adults in aged-care, group music-making can bring numerous physical and psychological benefits, ultimately improving their quality of life. However, personalising music-making to optimise these benefits is often difficult given their diverse ages, experiences, abilities, cognitive and motor skills, and their experience with music technology. Materialsandmethods:In this study, we conducted a 10-week group music-making intervention with twenty participants in an aged-care home, using a prototype digital musical instrument that we iteratively refined by following a user-centred design approach from direct resident feedback. The prototype instrument adopted a novel method for errorless learning in music-making settings, which we also refined, by increasing the difficulty level of the instrument's operation. We also assessed the residents' engagement with the sessions by obtaining feedback from caregivers and facilitators. Results:Results show that residents' enjoyment decreased as the complexity (difficulty) of our errorless learning implementation increased. We also found that resident engagement increased when changes to the prototype digital musical instrument were provided, but not when residents were giving feedback. Results also found that participation over the course of the intervention, and the number of songs played during each session also enhanced engagement. Conclusions: Overall, our results show the intervention was beneficial to residents, although we note some areas of enhancement for further interventions in designing prototype musical instruments for group music-making in aged-care settings. IMPLICATIONS FOR REHABILITATION Older adults positively engage with novel music technology, and do so increasingly over subsequent sessions. Repeated sessions may have the potential to enhance longer-term adoption of technologies as well as any rehabilitative effects of the group music-making activity. There is significant potential for residents with different abilities to all make music together, although to maximise the sustainability of the devices, the sessions, and the subsequent rehabilitative benefits, residents must be given the right adaptation for individual interfaces that balances ambition and ability. Rapid DMI prototyping positively enhances engagement among older adults, suggesting that in the case of a custom DMI, an upgrade schedule should be aligned with key rehabilitative milestones. Similarly, in the case of pre-developed digital music systems, resident exposure to new features or functionality should be strategically introduced, so as to maximise engagement for key phases of resident rehabilitation. Older adults positively engage with novel music technology, and do so increasingly over subsequent sessions. Repeated sessions may have the potential to enhance longer-term adoption of technologies as well as any rehabilitative effects of the group music-making activity. There is significant potential for residents with different abilities to all make music together, although to maximise the sustainability of the devices, the sessions, and the subsequent rehabilitative benefits, residents must be given the right adaptation for individual interfaces that balances ambition and ability. Rapid DMI prototyping positively enhances engagement among older adults, suggesting that in the case of a custom DMI, an upgrade schedule should be aligned with key rehabilitative milestones. Similarly, in the case of pre-developed digital music systems, resident exposure to new features or functionality should be strategically introduced, so as to maximise engagement for key phases of resident rehabilitation.