<qa>  What is the main goal of this research project?Cares of Alzheimers disease AD and related disorders are presenting a real public health challenge. Because of the limited effectiveness of pharmacological treatments, there is a growing interest in care approach based on nonpharmacological treatments, such as musical interventions. Several lines of evidence suggest that musical interventions could improve behaviour, emotion and even cognition in patients with AD. However, very few studies respond to the methodological constraints required for clinical controlled trials carried out in well selected groups of patients. The efficiency of such care approaches is not scientifically proved yet and the impact of musical interventions has rarely been compared to another pleasant intervention, leaving open the question about the specific benefits of music in patients with dementia. The main goal of this research project is to demonstrate short and longer-term efficiencies and the specificity of musical interventions in dementia by investigating their effects not only in patients but also in familial and professional caregivers. 