Sonata-Allegro Form

Continuing on last week’s article, we dive into a deeper and more complex form, sonata-allegro. This form is used mainly in classical music; understanding the inner workings of this form will lead to a higher appreciation of many classical works. It’s my belief that many people are turned off by classical music simply because they do not understand how sonata-allegro form functions.
Sonata form was fully developed during the Classical era (c. 1750 - c. 1827) and is utilized in almost all first movements of symphonies and almost all first movements of any solo sonata. The first main section of sonata form is the Exposition. This section presents all the material that will be used later on in the work. The exposition comprises of two parts, Theme A and Theme B. Theme A is always in the original key of the piece, or the tonic (I). After a modulatory section Theme B is presented in a different key, usually the dominant (V), but not necessarily. A small closing section may occur after this, followed always by a repeat sign.
The Development follows the exposition. Another way I’ve heard this described is an “excursion”. The development is easily recognized because it immediately follows a repeat sign. This section takes the ideas and motives of themes A and B and creatively alters, deconstructs and manipulates them. The Recapitulation follows the development, presenting Theme A’s original material as heard in the exposition. The only difference is that there is no modulation to Theme B; both themes should be in the same key (although many composers have sometimes broken this rule). After Theme B a coda may be presented, otherwise the piece will end. A visual representation may look like this:

Exposition                           Development
||Theme A ----Modulation----> Theme B [closing section]:|| Develops Themes A and B
I                    X (usually V)

Recapitulation
Theme A ---NO MODULATION--->Theme B [Coda] ||
I                    I (usually)

Listen to P.D.Q. Bach’s entertaining and hilarious description of sonata form. He presents the material in a funny but intellectual way that is easily grasped. The piece of music performed is Beethoven’s 5th Symphony, I. Allegro con brio. Go to imslp.org and search for a score to look at while you listen! See if you can identify all the parts!

Another very popular tune that is in sonata form is the I. Allegro from Mozart’s Piano Sonata in C Major, K. 545. Again, listen with the music in front of you and try to recognize all the different sections!

Sonata form is a fantastic way to design music, and is still used today. Having a strong grasp on this form will certainly pave the way to understanding classical music on a deeper level. Listen to sonatas of your favorite composers and see how they break the rules to come up with creative musical ideas!