Criticism and Sonata Form - Charles Rosen

Charles Rosen

In his influential books The Classical Style and Sonata Forms, Charles Rosen has attempted to understand why the particular arrangements of keys and themes used in classical sonata form have held such importance for classical composers and their listeners. Rosen conceives the classical era's sonata form movement as a kind of dramatic journey through the system of musical keys. Modulations that move upward in the circle of fifths (in the direction of the sharp keys) increase musical tension, and modulations that move downward reduce it. Sonata form first increases tension through the move to the dominant (the crucial musical event of the exposition), then increases tension further in the development through the exploration of remote keys. The recapitulation resolves all this tension by returning everything to the tonic. He also argues that, over time, this idea would become the basis for all musical movements, regardless of their formal plan.

The use of the circle of fifths makes sense of a number of observations about the deployment of keys in the classical sonata form:

• Use of keys other than the dominant for the second subject group generally go still higher than the dominant in the circle of fifths; see sonata form for details.
• Occasionally, the reappearance of the opening material at the beginning of the recapitulation is in the subdominant key (a famous example is Mozart's Piano Sonata K. 545), which serves the same resolving function as the tonic.
• Secondary developments often also reach the subdominant key, with equivalent resolving function.