Parkinson’s disease (PD) occurs in 1% of the population aged over 60. Changes in voice and speech are among the earliest and most prevalent symptoms of PD; reduced vocal intensity, monopitch, monoloudness, breathy and hoarse voice quality, imprecise articulation, vocal tremor, and abnormal tempo and rhythm. To date, research on singing and communication has focused more on the perceptual qualities of voice rather than rhythm. This study proposes an integrative measurement tool to evaluate the rehabilitative effect of music on targeted areas of communication function, activity, participation, and quality of life, and presents a case study to explore the proof of concept. The measurement tools comprise a set of objective measurement tasks and subjective self-rating scales. A single subject with Parkinson’s disease was recruited to participate in nine weekly one-hour intergenerational choir rehearsals. They were assessed prior, one week post and eight weeks post participation. Twenty-one songs with carrying rhythmic complexity were taught and practised. Outcomes demonstrated change in the intended direction on objective measure, with smaller changes on the subjective measures. The authors advocate that this measurement tool holds promise as an outcome for a future full effectiveness study. Demonstrating effectiveness of behavioural interventions for people with progressive disease is extremely challenging.