Authenticity is a concept of personality in the fields of psychology, existential psychotherapy, existentialist philosophy, and aesthetics. In existentialism, authenticity is the degree to which a person's actions are congruent with his or her values and desires, despite external pressures to social conformity. The conscious Self comes to terms with the condition of Geworfenheit, of having been thrown into an absurd world (without values and without meaning) not of his or her own making, thereby encountering external forces and influences different from and other than the Self. In human relations, a person’s lack of authenticity is considered bad faith in dealing with other people and with one's self; thus, authenticity is in the instruction of the Oracle of Delphi: “Know thyself.”

Concerning authenticity in art, the philosophers Jean Paul Sartre and Theodor Adorno held opposing views and opinions about jazz, a genre of American music; Sartre said that jazz is authentic and Adorno said that jazz is inauthentic. Many musical subcultures require artistic authenticity, lest the community consider an artist to be a poseur for lacking authenticity (creative, musical, personal); artistic authenticity is integral to many genres of music, including but not limited to genres of rock (such as punk rock and heavy metal), club music (such as house and techno), and hip-hop.