First off, I know very little about the law whatsoever - so please bear with me on this one! :) In my spare time, I've being making instrumental accompaniments to some of my favourites musicals and pop songs. The scores are my own work in that I listen to the songs and pick out what I can hear and write in on the stave. Obviously, the songs that I am writing the accompaniments from are not my own. I use two software: Sibelius and Garage Band.
I've let some of my musician friends listen to them and they were impressed with the quality and told me to sell them for some money instead of keeping them to myself. My question is, what are the laws surrounding this? If I've made the accompaniment all by myself by listening to the original tracks then surely it's okay for me to sell them? If I were to sell them directly to buyers, what would I need to do to cover my back so I don't get accused of something like plagiarism?
Thanks a lot! I'm really sorry for my lack of knowledge in this area.