The central idea of The Song of the Lark is that Thea, a great singer, must follow her own path and avoid conventionality to achieve artistic success. Her family does not understand her, and her friend Dr. Archie, who saves her life as a girl, believes that they don't understand how special she is.
Thea does not follow a conventional path. She befriends people in her town of Moonstone, Colorado, whom others shun, such as Professor Wunsch, her drunk music teacher. She also delights in the company of Spanish Johnny, who is also a drunk. When the man who intended on marrying her dies and leaves her money, she goes to Chicago to study music. In the midst of her career, she does not go home for her mother's funeral. She shuns what is expected and conventional. Though Thea is not heartless, she must follow the artist's path and her own instinctual wanderings to achieve greatness as a musician.