“Personality theory is focused on the thoughts, feelings and behaviour of human beings, including their interactions with their social environment” (Funder, 1994). From this comment it could be suggested that personality is made up of the characteristic patterns of thoughts, feelings and behaviours that make a person unique. In addition to this, Piedmont supports that personality come up from inside the individual and remains fairly consistent throughout life  .
Ancient Greeks were the first who talked about personality and the elements that affect it, which are the earth, the water, the air and the fire. Hippocrates and Galen supported that character is attributed to the mixing of the juices that exist in the body, such as blood, yellow and black bile and the phlegm. From this, four types of character are created: the choleric, the melancholic, the sanguine and phlegmatic. During the years, several theories have been developed for identifying the traits and structure of human personality and each of which was influenced by the ideological and methodological background of the founder such as Freud, Cattell, Eysenck, Hartmann, Jung. Although all these considerations have their strengths and manage to significantly penetrate the deeper essence of the concept of “personality”, nowadays a new theory have been established upon which most modern psychologists of personality seem to agree. This new approach is called “Big Five Dimensions” and argues that human personality can be fully described by five key factors. These factors are:
Openness to experience: which describes the ability to open and explore unknown situations, to recruit new experiences (imagination, broad range of interests)
Conscientiousness: which focuses on whether the conduct of the individual aims to achieve an end and is governed by inner values, standards and ethics(thoughtfulness, organized, planful)
Extraversion: which evaluates the quality and intensity of social relationships of individuals (sociability, talkativeness, excitability)
Agreeableness: which examines the quality of the relationship of the individual with others and with himself ( trust, altruism, kindness, affection)
Neuroticism: which refers to emotional balance and the adjustment of the individual (emotional instability, anxiety, moodiness, irritability, sadness)
Another personality inventory was the one of Eyesenck which measures personality using two scales. Introversion-extraversion, stability-instability. Eysencks theory was based on the four temperaments methodologies, first formalised and popularised by ancient Greeks. According to Eysenck, there are four types of personality. The choleric types are the unstable extraverts and they have qualities such as touchy, aggressive, changeable, optimistic, active, excitable and restless. The melancholic types are the unstable introverts their qualities are such as quiet, reserved, pessimistic, sober, rigid, anxious and moody. Sanguine types are the stable extraverts they are talkative, outgoing, responsive, lively, easygoing, carefree, leadership and sociable. Phlegmatic are the stable introvert and they are calm, even-tempered, reliable, controlled, peaceful, thoughtful, careful and passive.
It is widely accepted that human behaviour is shaped by the influence of different factors, and this includes a musician’s personality as well. Such factors include both genetic and environmental influences. Becoming a musician does not depend on genetic reasons per se or solely on how effective the learning process is. Mainly it is based on a complicated combination of different factors which influence every individual in different proportions.
Nearly all researches agree that human traits are jointly determined by both nature and nurture, though they may disagree about the relative contribution of each”. (Ceci and Wiliams, 2000). Genetic structure may be a factor that influences someone to become a musician. Some people are born with a music gift and through years in combination with the environment they can develop it. However, the importance of genetic influences decreases over time as individual experiences and social environment becomes more important.
“Social environment help determine the status of individual, the roles they perform, the duties they are bound by and the privileges they enjoy” (Pervin and Jones, 2001). Indeed, the social environment can be a “drive wheel” for someone to develop a musical gift. By action and by example, parents shape the lives the behavior and the choices of their children from birth through adulthood (Ceci and Williams,1999).  If the child is raised in a musical environment, with parents’ musicians or listening to music all the time, then the possibility of becoming a musician is higher. This can also be seen in the past, in Baroque, Classical and Romantic eras, where most famous composers or pianists had great music parental guidance by their musician parents. Also if a child decides to be a musician, he often needs the support of the family in order to maintain his interest in music from an early age. Feltovic (2006) stated that “The amount of instrumental practice from an early age is of vital importance for later musical performance . In addition, if a child is associated with other children related to music, then the possibilities to develop an interest in music are increased.
Previous findings on musical development have rarely indicated that learning efficiency is an essential aspect of musical expertise. (Gaunt & Hallam, 2009)
Indeed, effective learning and a teacher’s influence also play an important role on children’s performance. Teachers could positively affect the interest of a student for music by offering encouragement, and also negatively discourage a student by failing to support the child properly. The effective learning and good teachers who truly value students might turn children into music For example the teacher can increase the level of interest in music by making music learning more enjoyable for students. Teachers can have a great influence on children thus I believe that if children love the teacher, then they are likely to love music as well.
Finally socio- economic conditions and many other unpredictable factors may affect a child positively or negatively to follow a musical path. Music education in developing countries appears not to have been a major priority since the lack of financial resources prevents these countries to meet their citizen’s educational needs. For example in Africa only 4.6%  of all schools in the country have music rooms.
After analysing the reasons that may influence someone to become a musician instead of another, the next step is to identify possible factors that may determine someone’s personality after becoming a musician. Does every type of music affect musician’s personality the same level? Is each kind of music related to specific emotional characteristics?
“Research has shown that various aspects of our personality are related to the types of music that we choose” (Mitch Beavers and Lauren Mutispaugh). In their research on whether personality predicts music preference, observe that those who listen to classical music appear to be less agreeable and prefer sad music. The same research detects that individuals who listen to heavy metal music were low conscientiousness with low emotional stability.
Rentfrow and Gosling (2003) using the Short test of music preference, they concluded that listeners of the same kind of music, had similar characteristics. Country music lovers tend to be low in openness to experiences, but high in conscientiousness. They also appear to prefer music that is simpler in nature. Jazz music lovers are more open to experiences and prefer complex music. Blues music listeners prefer music that is more complex and sad. Folk, rock, and heavy metal tend to prefer more complex music. Pop listeners tend to prefer more simple music. Religious music appears to have higher self-esteem and prefer happy music. Classical music and soundtracks appear to less agreeable and prefer more complex and sad music. Rap and hip-hop seem to be more agreeable, extraverted, and to prefer music that is happy and simple in nature. Heavy metal music appears to be low in both conscientiousness and emotional stability.
In a research on Classical music preferences, Burt found that the participant’s tastes differed according to the extraversion, introversion but also on the emotional stability. In his study, Burt concluded that stable extraverts preferred classical and baroque music (Handel, Verdi, Brahms) which possessed characteristics like solidity, balance, brightness and predictability. On the other hand, stable introverts also preferred classical and baroque period but with a preference on absolute, intellectual and cognitive music like Bach. Moreover, Burt found that unstable extraverts’ preferred romantic music which has strong contrasts is emotional and vigorous (Wagner, Liszt, Berloz). In contrast, unstable introverts also preferred romantic music but impressionistic and mystical pieces like Debussy’s, Chopin’s and Weber’s (cited in Kemp, 1996). 
According to a research by Delsing, Bogt, Engels and Meeus,  heavy metal, punk, gothic and rock listeners were found to be related to openness to experience but not to conscientiousness and to extraversion. Jazz, classical and gospel listeners tend to be high on conscientiousness, agreeableness and openness to experience but low on emotional stability. Hip hop, soul, rap trance and techno listeners were found related to extraversion and agreeableness.
Finally, a research by Professor Adrian North, notes that heavy metal and classical listeners have similar emotional characteristics since both are creative, calm and unsociable.
Furthermore, another factor that determines personality is the kind of gender. Indeed, the effect that music has on personality must be analysed in proportion to the gender of every individual. Even when both man and woman are related to a specific kind of music, it has been noticed that still their personality characteristics are not the same. In a research by Eric Lacourse, Michel Claes and Martin Villeneuve (2001) about heavy metal music and adolescent suicidal risk , it seems that girls fan of this kind of music, are more suicidal than boys.
Recently there have been many research efforts on whether musician tend to embody certain personality type. The literature offers some evidence regarding links between personality and musician activity.
Wayne Gillespie and Brett Mayors, by examining rock and popular musicians who completed the Revised NEO Personality Inventory and a questionnaire, conclude that Rock musicians share a common profile. Rock musicians were high neurotic, open to experience, average extravert, low agreeable and conscientious. On the other hand, in a research by Dyce and O’ Connor, concluded that popular musicians are extraverted, emotionally unstable and imaginative.
In a research about orchestral instrumentalists, Langendorfer concluded that string players had significant high scores on conscientiousness than woodwind and brass players. 
In his book the musical temperament, Anthony Kemp states that the musician’s temperament involves a proclivity to sensitivity, introversion, anxiety, intelligence, and independence (Kemp 1996). Buttsworth and Smith (1995) indicate that performing musicians are more emotionally stable and sensitive. Singers appear to differ from instrumentalists and share personality traits with dancers, such as emotionality and hypochondrias are (Marchant-Haycox& Wilson, 1992).
In their book Parncutt and Mcpherson  , state those children who are more introverted, studious and quieter usually tend to prefer string instruments, while more extroverted and socially outgoing prefer brass instruments. Singers also tend to be more extraverted sensitive and imaginative, whereas keyboard players tend to be also extraverted but not as much as the singers and the brass players.
Music and personality are two issues that cannot be analyzed in a 20 minutes presentation or in a 2000 words essay. This presentation answered three questions that are important as far as concern music and personality. Which factors affect someones personality to become a musician? What types of music do different personalities tend to prefer? Do musicians tend to embody certain personality type? My conclusion is that both nature and nurture, social and musical environment, peers, socio-economic conditions, teachers and effective learning are factors that may influence someone to become a musician. I believe that music do not influence personality, but there is a direct relation between the music we listen and to our personality, which includes our thoughts, lifestyles, places we choose for entertainment, clothes, companionship. Because of our personality we choose certain types of music to listen to or to become musicians of the kind of music that reflects our personality.
Of course most musicians have similar elements on their personality like sensitivity, anxiety, introversion, but this is not essential for all. The musicians expresses some feelings or experiences, based from their life, like poorness, parents divorce or even a death of a close person. Some musicians may live the same experiences, but because of the social environment may develop a different type of personality. Through music, the artist communicates his thoughts which will be influenced from the era he lives in.
Concluding I believe that if all musicians had the same personality, then music would have been the same.