"Music speaks what cannot be expressed, soothes the mind and gives it rest; heals the heart and makes it whole, flows from heaven to the soul." The author of this quote is yet to be known, but we can agree that clearly, music is a fairly emotional process. If you're flipping through the radio stations and you hear a snippet of "Don't Stop Believing," you might be tempted to pause on that station for the duration of the song and sing your heart out. Or, if you hear Pharrell's "Happy," you might start bobbing your head from side to side with a goofy grin on your face, pulling some embarrassing dance moves you maybe didn't know you had in your sleeve. Music is a fairly cathartic, relatable process of emotion we undergo, expressing, as the quote says, that which cannot be expressed. But sometimes, the emotions that one experiences in listening to music are too much to bear, and they need to be released from the abstract world of listening to and being absorbed in music, and into the physical, tangible world. In a sense, we need access to our emotions. This is where the element of dance comes in.

   Dance can be characterized according to dance researcher and anthropologist Judith Lynne Hanna's criteria: movements must be purposeful, intentionally rhythmical, culturally patterned, and nonverbal. Furthermore, such movements must possess some aesthetic value and conform to the "group's notions of appropriateness and competency" (Francis 210). In other words, dance is an important cultural component, since it is used to convey certain meanings, namely, emotions. Dance is one form of what Planalp and Kleine define as expressive emotional communication, in which "expressions have no particular purpose, other than to release emotion…often responding to recorded materials with no chance that the materials will respond back" (Planalp & Kleine 57-59). Dance, then, is a response to that which goes on people's environments, a mode of communication through which they express complex emotion, perhaps resembling those same ones that are reflected in music. More importantly, dance is a cultural response aiming to achieve no other purpose other than to simply to let out.

   The origins of tango are hard to pinpoint due to its unrecorded history, but the generally accepted theory holds that it saw its rise in the mid-nineteenth century, when the African slave trade brought local traditions and dances to the working-class neighborhoods of Argentina. At the time, Argentina was experiencing heavy immigration, bringing in cultural influences from Africa, Spain, Italy, Britain, Poland, and Russia to cultivate the tango dance. "Traditional polkas, waltzes, and mazurkas were mixed with the popular habanera from Cuba and the candombe rhythms of Africa" to create a new genre of dance that conveyed the sense of loss and displacement the immigrants, who were typically poor, single men, faced ("Argentine Tango: A Brief History"). This is where tango derives its nostalgic, melancholy nature from, and often, tango is meant to be an intensely dramatic experience. Tango utilizes a syncopated ostinato rhythm and is characterized by sudden change of dynamics, frequent use of bent notes called glissandi, smooth song-like passages, and staccato phrases that contribute to the dramatic intensity (BBC). A prominent feature in tango is the ability to improvise, which is no easy feat. Having the ability to improvise in tango requires having knowledge of tango music and its patterns in figures and structural elements, as well as an ability to explore one's culturally allowed options and an ability to imagine. "Dancing tango socially is an improvisational exercise in which the conscious and unconscious minds work together to create a dance from the options one has learned. Relaxing and enjoying the moment helps open the channels to the unconscious mind and better enables one to dance in a creative flow" ("Learning to Dance Argentine Tango Improvisationally"). The more one learns and understands how to move the body in such a way as to align with the culturally accepted ways to move, the more one learns to adapt the mind, adjusting itself in such a manner as to fit the cultural needs. This makes sense, as tango arose as a way to adapt to the difficult life that being a working-class immigrant would demand. Tango expresses anguish in a dramatic manner so as to exude joy from catharsis. But how does this process of catharsis work?

   Its quality of improvisation serves therapeutic value for individuals afflicted with Parkinson's disease. Parkinson's disease is a neurodegenerative disorder caused by the loss of dopaminergic neurons in the substantia nigra of the basal ganglia, which facilitates slowness or absence of movement, rigidity, and a resting tremor typically in the hands and fingers (UTHealth). The death of such neurons plays a significant role in the development of depression in PD patients, since they produce the primarily pleasure-inducing neurotransmitter known as dopamine. Unfortunately, depression and PD are stuck in a loop of negative feedback, since depression can intensify both motor and cognitive symptoms of PD. Treating such depression, however, can actually improve both quality of life and movement. There are a wide array of treatments used to combat depression and PD separately, including exercise programs and other such physical therapy ("Depression"). Tango is a method used for both on separate occasions. In one study, individuals with self-declared depression were divided into groups taking either an Argentine tango dance or mindfulness meditation class to assess which method would be more beneficial for the depressed individual. Tango turned out to be the better option of the two, as depression levels for individuals in the tango class were significantly decreased in comparison of the pre- and post-tests. This owes to the fact that tango's "awareness of current experience is likely to interrupt an individual's thoughts about their pasts and fears about the future, so potentially lessening association between negative thoughts and possible affective symptoms" (Pinniger et al). In another study assessing the effects of different programs designed to help facilitate mobility in PD patients, individuals with PD were divided into groups performing the Argentine tango dance and performing regular exercise. It was discovered that "those who participated in the Argentine tango dance group improved on measures of balance and mobility due to the engagement of multitasking activity, including activities such as turning, initiation of movement, and moving at a variety of speeds and often in close proximity to a partner" (Hackney et al). It is evident that such mental activity, such as drawing from knowledge of tango's structural elements and conjuring up ways to integrate those elements into a new sub-form of sorts of dance, detracts from otherwise prevalent depressive thoughts. If tango can alleviate the effects of both depression and the motor hindrances induced by PD, then it would make sense that tango can be used as a form of therapy to help improve the quality of Parkinson's patients.

   We have deduced so far that dance is a means of expressing intense emotion through physical movement. But what about music, its loyal companion, container of the absolute most intensely felt emotions yet? What about the cathartic power of music? It turns out that when we listen to music, numerous parts of our brain are simultaneously activated, namely, components of the limbic system that are responsible for regulating primitive emotions such as fear, pleasure, and anger, as well as drives, such as sex and hunger. This helps further explain why music in general can be used to help treat Parkinson's disease. It also helps to explain, for instance, how children with autism spectrum disorder process emotion. A study using functional MRI compared brain activity in autistic children and in neurotypical children, and concluded that "children with autistic spectrum disorder are as accurate as neurotypical children at identifying emotion in music and show the same level of brain activation" (Gaidos & Wolinsky 26-28)." "Studies show that listening to music stimulates brain areas specialized for imitation and empathy that contain what researchers call mirror neurons. These brain circuits, first described in monkeys, act like mirrors in the mind, reflecting others' actions and intentions as if they were one's own. The neurons allow you to feel loved ones' pain or simulate their actions, even if only in your mind" (Gaidos & Wolinsky 29). The development of mirror neurons is an evolutionary phenomenon designed to enable humans to feel empathy for one another to connect. Therefore, as Aristotle says, humans are social creatures and society precedes the individual; we as humans have a psychological need to band together, looking for and providing support for one another as we progress through life. If music can activate these mirror neurons, then music, too, serves as a communicate strategy of one's pain, anger, joy, and all other such emotions.

   This view might be summed up in the notion that music is a universal language. But not all agree with this and in fact contest the opposite, since language is learned first as a "vocal performance" where infants use rhythm, timbral contrast, and melodic contour as primitive measures of learning semantic and syntactic aspects of language (Brandt et al). Considering this, we can entertain the idea that perhaps if the ability to produce or understand language is lost, as in the case of aphasia, then music can help restore linguistic abilities. Broca's aphasia, also known as the loss of the ability to produce language, is controlled in a region of the frontal lobe of the brain's left hemisphere called Broca's area named after Paul Broca. It is a condition that can be treated with melodic intonation therapy, which plays on the concept that language, specifically speech, is learned as a form of music. Even though aphasia patients lose the ability to produce speech, they retain their ability to sing. Thus, melodic intonation therapy aims to reteach language to aphasic patients by stressing melodic patterns in speech. This method works because such musical features induce hyperactivity in areas of the brain's right hemisphere that are analogous to Broca's area; such malignant hyperactivity then inhibits Broca's area. The solution to this, interestingly, is singing and melodic intonation: "by engaging the right-hemisphere circuits in normal activity, they disengage them from pathological activity," but "as the left Broca's area is released from inhibition, it can exert a suppressant action on the ‘right Broca's area.' A vicious circle, in short, is replaced by a therapeutic one" (Sacks 221). In sum, music can be used to train the right hemisphere to supplant linguistic ability otherwise impaired in the left hemisphere. For melodic intonation therapy to truly work, however, there needs to be a connection between the therapist and the patient, "a relationship which involves not only musical and vocal interaction but physical contact, gesture, imitation of movement, and prosody. [...] This intimate working together, this working in tandem, depends on mirror neurons throughout the brain, which enable the patient not only to imitate but to incorporate the actions or abilities of others" (Sacks 219). We have already seen how mirror neurons serve as a way to connect people; this, however, highlights the process of learning, part of which includes imitation, explaining the learning process behind being a successful tango dance partner. "Listening to a favorite tune will light up the brain's reward centers—and boost activity of the brain chemical dopamine, a molecule involved in desire and reward" (Gaidos et al 26). If the patient likes the caregiver, they will likely be partial to the sounds they will need to imitate. But what if the patient is not trying to imitate the sounds of a language to learn it?

   In a study exploring the effect of vocally expressed emotions and moods in the form of song between caregivers and patients with dementia. Morning care sessions were run in three different ways, which the researchers called "usual," in which no music was played during the session; "background music," to indicate background music was played; and "caregiver singing," with the caregiver serenading the patient. Out of the three methods, background music and caregiver singing proved the most effective in terms of instilling feelings of warmth and compassion within the dementia patient. Rather than being hostile and exhibiting aggressive behavior, patients were found visibly enjoying the caregiver's own voice, smiling and conversing politely with the caregiver. One patient sang along with the caregiver in a delighted manner, as if "aware of the meaning of the texts, and responded as though they knew and understood the content. […] During such situations, PWDs concentrated both physically and emotionally on the caregiver. Some PWDs seemed to experience and share a remarkable time with the caregivers" (Gotell et al). This further bolsters the idea that music unites individuals and sets forth connections otherwise not easily made between individuals.

   Music, clearly, has a wide range of abilities. Its ability to express emotions evokes within us our own primitive fears, pleasures, angers, and drives connects us to one another; through music, we empathize with one another and forge meaningful connections that are crucial to our survival as a race. Since music is a key component to any culture, it is used also as a way to remember the times that have preceded our own, the people and the history surrounding the development of entire genres of music. We use music to connect not only to those living in the present, among ourselves, but also with the past, causing one to feel an old, natural feeling, an awakening from deep within themselves as old as time. Music feels natural because it is natural; it serves as the very basis of who we are as individuals and as a society. Knowing what music is capable of doing, and with so many scientific studies conducted in the past and ongoing today, I wonder if the therapeutic aspects of music can be more strongly integrated into the healthcare system. Music therapy research still has a long way to go before it can start to be considered more seriously by healthcare officials, but the medical field bears constant witness to rapid advancements. And certainly, music therapy is an exciting line of neurological research to pursue.