Hello there:
In order to compose for Pipe organ you really need to understand so many things. First you need to know how to play, i would suggest you take lessons from the best organist you can find. THen you need to learn the history and structure of the instrument. THis is a huge topic, so do your homework. I have a lot of experiance with pipe organs around the world and recently played the only bamboo pipe organ in manila phillipines. Las pinas city to be exact.
I do not mean to discourage you from trying to write for the instrument, but really if you do not know the instrument, then you will have difficulty. The history of the registrations differ depending on country of orgin where the organ was built or the time period etc.
My name is jeff
and you can reach me at jeff@lessonsbyjeff.com
i soon hope to play the klais organ in malaysia kuala lampur
my friend in phills learned to build organs from klais
he is the only builder in philippines
I hope some of this info helps
Get in touch
Jeff :D