Dementia negatively affects the wellbeing of both caregivers and care recipients. Community-based therapeutic choir singing offers opportunities for music participation and social engagement that are accessible and mutually enjoyable for people with dementia and their family caregivers and promotes shared and meaningful musical interactions, which may support relationship quality. This study aimed to investigate the impact of the Remini-Sing therapeutic choir intervention on relationship quality, quality of life, depression, and social connectedness for dyads, as well as caregiver burden and care recipient anxiety. A randomized-controlled trial design was used with a target sample of 180 dyads. Due to recruitment difficulties, 34 participant dyads were recruited and randomly assigned to a 20-week group singing condition (n = 16) or a waitlisted control group (n = 18). Participant dyads consisted of people with dementia and their family caregivers who resided at home in the community. The Remini-Sing therapeutic choirs were held in community settings. Assessments were conducted by masked assessors at baseline, 11 weeks, and 21 weeks. Twenty-one dyads completed assessments at the primary timepoint (Week 11). Issues with recruitment and retention resulted in an unpowered study with no statistically significant findings. Mean decreases in anxiety and depression for choir participants with dementia were supported by medium to large effect sizes, indicating a potential intervention effect to be explored in future powered studies. Key learnings related to study design are discussed regarding recruitment, retention, participant burden, and sustainability, with recommendations made for future dementia research.