The purpose of this Notice of Funding Opportunity (NOFO) is to support proof-of-concept feasibility trials guided by the NIH Music-based Interventions (MBI) Toolkit for research on brain disorders of aging. These early phase clinical trials will generate evidence supporting the validity of the NIH MBI Toolkits guiding principles as well as the necessary pilot data to design a subsequent clinical efficacy or effectiveness study (or pragmatic clinical trial) using music-based interventions in the context of brain disorders of aging, including but not limited to Alzheimers disease and Alzheimers disease-related dementias, Parkinsons disease, and stroke. The data collected should address gaps in scientific knowledge in order to facilitate development of a competitive large-scale clinical trial.