First published in 1948, "Structural Functions of Harmony" is Schoenberg's final theoretical work and contains his ultimate thoughts on classical and romantic harmony. The initial chapters are a review of the basics in early Harmony Theory. The following chapters demonstrate the concept of 'monotonicity', where all modulations to different keys within a movement are analyzed not in relation to each other but in relation to a central tonality (tonic) as the center of all harmonic changes. Schoenberg's musical examples range from entire developmental sections of classical symphonies to analyses of the harmonic developments of Strauss, Debussy, Reger, and his own early music.