Creating a Structure
It is a good idea to start your composition by outlining the whole structure of the composition. By building a skeleton structure first, you are more likely to create a piece with a good form and harmonic progressions. Without a proper structure in place, you risk writing a composition which sounds random, or you may find yourself getting lost by modulating to a key that is so distant, it is difficult to return to the home again.
You can make some planning decisions before you start to compose. In fact, you can even make some of these decisions before you start the exam, which is another advantage: advance planning can save you time on exam day.
Here are some things which you should consider planning before you begin to compose:
1. Length. The wording of the question normally stipulates “not less than 12 bars”. Choose either 12 or 16 bars, as these allow for balanced phrases. There is no advantage in writing more than 16 bars, and a longer composition will simply take you longer to write.
2. Form. We called the first section of a composition “A”; this will last for a certain number of bars, then a contrasting section will be “B”. With these two letters (A and B,) you can make several types of overall pattern, or “form” for your composition, for example AB, ABA, ABAB, ABBA and so on. The form you choose is completely up to you.
Keep in mind that with a form such as ABBA, although you are restating an idea, you should avoid making the sections identical, so in ABBA, the second B should be connected to the first, without being exactly the same. As you are writing a very short composition, it is best to restrict your piece to two main ideas.
3. Phrase length. Work out how many bars each section will take. In most cases, the best way forward will be to make your ideas the same length – four bars per phrase is an excellent choice.
4. Modulations. How many often will you change key? You can work out in advance a choice of related keys, for example moving to the relative key for the contrasting B section, then restating the opening material in the subdominant, before returning to the home key by the end.