A friend sent a video of a psychiatrist discussing his take on narcissistic personality disorder, which turned out to be a report on his own personal brand of narcissism. I found it to be engaging, but ultimately unrecognizable. Since I live a musical life, I encounter all sorts of people who could be labeled "narcissists." I would venture to say that all musicians have some narcissistic traits, but the presence of narcissism in musicians is really about degree, and about balancing narcissistic traits with other traits.
Someone in music who has absolute pitch, physical skills, a good memory, and a healthy helping of intelligence could easily believe that those traits make him or her "better" than others. I have a good friend who instills the importance of humility into her students, particularly the ones who have a lot of talent, intelligence, and ability. She instills into them the belief that because they have talent and ability it is their responsibility to work extremely hard and remain humble in the face of a much larger force that allows music to happen. She has been doing this for a long time, and it seems to work quite well. I don't know about these students' inner sense of self (who does but each individual), but I do know that the way they present themselves in social and musical situations reflects a healthy balance of self-confidence and humility.
I believe that we all have a degree of narcissism that is hard-wired into us. If we didn't have it, we would not have survived infancy. Some of us have special physical traits that we either capitalize upon or ignore. Someone, for example, who is particularly attractive and is aware of his or her attractiveness will live a life that is "informed" by a certain physical presence whether he or she acknowledges it or not. Someone who is not conventionally attractive but has a highly developed intellect could cultivate a higher ratio of narcissism to humility.
I wonder if the 21st-century power of instant and potentially far-reaching communication can throw the narcissistic/humility balance off, leaving us in a world of people more interested in the reactions of people to what they say and do than in pursuing interests, finding community, and sharing friendship.