In this study we will examine the effectiveness of a new therapeutic tool, known as Rhythmic Sensory Stimulation, as an adjunctive treatment for Major Depressive Disorder. Rhythmic Sensory Stimulation is a non-invasive brain stimulation technique that uses periodic pulses of light, sound, or tactile stimulus, to induce changes in the patterns of brain activity. Participants in this study will undertake 30 minutes of daily music intervention self-administered at home, for 5 days per week, for a total of 5 weeks. We will assess depression symptoms, sleep quality, quality of life, and brain activity pre- and post-treatment.