"Maestro" is a novel that has two of the major themes of love and death, entwined within the story on many levels to a great extent. It explores physical factors of these themes, such as the death of the Maestro and then it explores non-physical factors such as the death of Paul's childhood. Love, like death, is a theme that runs throughout the novel and can be seen in many of the experiences Paul and Keller go through. Examples of this are Paul's love for Rosie, Keller and Paul's love for each other and their love and passion for music.
The book explores both Paul's and Keller's love of great music. It is Keller's means of survival and he can never turn away from it. After his family dies he dismisses his love of the Romantics and seeks refuge in the technical safety of Mozart and Bach "as if seeking some kind of ultimate discipline, some perfect control to set against the treacheries of emotion" (pg 50). He could no longer stand the Romantics because of the pain that listening to them caused him. It continually reminded him of his arrogance in thinking that "[no one] would harm the wife of Eduard Keller" (pg 117). Keller blamed himself entirely for his family's death, because ironically at the time they were taken away, Keller was performing for Hitler. In failing to protect his family from the Nazi threat because of his arrogance, Keller destroys a source of great love (his family) and destroys his love for great music also. Once he denies his love of passionate music, however, he dies emotionally and so in a way dies with his family in a Nazi concentration camp like the world believes he does.
Paul's life is also shaped by music and his love of it. As Paul grows he learns to respond to music in an emotional way rather than intellectually. Sadly, however, he never develops his talent to be a first-rate concert pianist because Keller had lost his ability to teach his student to play with "rubato".