QUOTE(notmusimum @ Jan 9 2008, 04:24 PM)

How do people learn to compose? Can anyone recommend any good starting materials?
I am from the US and Canada, so I am not familiar at all with the requirements for the GCSE and LCM in composition.
I agree with dcmbarton that it is best to compose, then try to get feedback from performers and teachers.
Composition lessons can be quite expensive as good composition teachers tend to hold higher degrees and teach at conservatories and universities. But if your daughter is really keen on composing, it may be a good idea to take composition lessons, even only sporadically. One advantage of studying composition with someone with a conservatory or university affiliation is that there will be a better chance of getting the music played by competent performers.
As a start, I recommend Arnold Schoenberg's book Fundamentals of Musical Composition. One could argue that this book is more like a theoretical treatise than a composition manual, but it gives clues to beginning composers how to develop a small musical idea into a larger structure. Most of the examples in the book are drawn from the Classical repertoire, but the ideas are applicable to music of different styles.