A few years ago I wrote a post concerning my checkered history in relation to musical forms. Before I knew what they were, I dismissed them as superficial. I had no idea the kind of power that organized patterns of repetition had in making a piece of music into something other than a collection of melodies and harmonies. I thought that form was taught to students because it was something that could be taught. I thought that thinking about form would remove the "mystery" in the music that I found so attractive. I was so terribly wrong. There is a great deal more mystery in the observation of mastery, especially after you have tried hand at composing music in traditional forms yourself.
It wasn't until I started teaching students about form that I learned to have a deep appreciation for form and its organizing qualities. I have developed an even deeper appreciation for the ways that great composers have been able to manipulate them, and my appreciation and fascination continues to grow. Perhaps one of the things that makes a great composer great is his or her ability to use form to great advantage. Learning to understand and appreciate a great piece of music (at least from the 18th and 19th centuries) has become, for me, learning to understand and appreciate the way the composer has organized the musical materials into the cosy and familiar forms that were in common use.
A person's reaction to musical form can be analogous to a person's reaction to a house. It may be attractive from the street, from the outside. You could spend your whole life appreciating a beautiful house from its exterior, and perhaps its yard. I spent a great deal of my life looking at music from the outside. During my musical travels, I have found that a great many performing musicians only look at the houses and yards of music.
When you step inside that house and see how the rooms are organized, the house has more meaning, even a house with the normal array of rooms and the addition of a finished basement and a sun porch. When you look at the woodwork, and the quality of building materials, the location of the house in relation to natural light, it gains even more meaning. If the house has built-in secret passages, dumb-waiters, and back staircases, or false bookcases that turn into doors that lead to hidden rooms, it becomes all the more exciting.
If the infrastructure (like the plumbing, electricity, and heating) is inventive, practical, and functional, you know that the house would be a comfortable place to live (this would be analogous to the playability of the piece). Then you get to the furnishings and the lighting, things that can change from owner to owner (and, of course, is analogous to the interpretation of the piece by various people over time). When you go back outside, and look at the house from the street, your experience is different. Completely different.
It is the same with music, and with only a little bit of information you can become an "insider" when listening to a piece of music. Using a score helps, but you can also follow forms from simply listening. Actually it is not "simply" listening: as soon as you start to pay attention, it becomes close listening.
Once you get the hang of it, it is fun to compare Mozart's development sections with Haydn's (before and after Mozart discovered the Haydn Opus 33 quartets), and with Beethoven's. It is fun to look at the way Brahms, Mendelssohn, Schubert, and Schumann (just for a start) used the various forms. Eventually the results of careful observation can clue you into a bit of understanding of the real individual genius of each composer, as well as what each saw in the other(s). It is fun to look at the way these composers treated the form of the Minuet, and observe how seemingly simple elements can render so much variety. It is fun to see just how complicated a Rondo can be, or how closely it can approach Sonata Form and still be considered a Rondo. Variation form is a world unto itself.
I think that being able to follow the logic of a movement written in any of the classical forms does a great deal to increase intelligence, or at least increase attention span and engagement in the elements at play in a piece of music.
Perhaps this is the real "Mozart Effect." It is in the act of paying attention to something over time that we increase our ability to observe and identify patterns. It is rewarding at every level, from the simple division of a piece into sections. You can label them A, B, C, "First Theme," "Second Theme," "Transition," "Development," and so on, or you can make up your own names (perhaps proper names, colors, temperatures, textures, flavors, animals). Children are as adept at this kind of observation as adults, but perhaps they can be more creative about it because they are children. There is no reason that creative thinking has to be abandoned after childhood, and there is nothing barring any music-loving person from entering into the interior of a piece of music. We all just need to keep our ears open, and allow our jaws to drop from time to time, while our minds expand.