Researchers and practitioners face the dilemma of choosing music therapy (acoustic) or art therapy (visual) for mental health management. Construal level theory (CLT) resolves this dilemma and suggests that abstract purposes result in longer predicted durations for the intended project, and a concrete method results in a shorter predicted duration for real practice. Inferentially, a longer duration estimate implies music therapy, and a shorter duration estimate implies visual therapy. Does this assumption hold in innovative clinical therapy projects for mental well-being? This study addresses this question by using clinical trial data from music and visual art therapy interventions. The results from the clinical trial data show that abstract purpose is perceived as distant and lengthy; therefore, music therapy is associated with a longer predicted duration. The concrete purpose is proximal and short; therefore, art therapy is associated with a shorter predicted duration. However, task complexity (design scope) has contingent effects on estimates whether they involve acoustic or visual technologies (music versus art). The study contributes to the application of CLT with temporal estimates. From an empirical standpoint, it provides insights into the anticipations of experimenters designing the context and methodology of the study. From a practical perspective, the results of this study offer valuable cues for decision-making, planning, and defining milestones within and between therapies, technologies and practitioners.