I love to create instant music when I lucid dream. I just create the pure sound without worrying about instruments. Sometimes I'll work with an orchestral score, fascinated at how I can direct and score the different instruments, improvising as I go. But memory is a bitch. A few nights ago I created an entire progressive rock piece complete with this absolutely beautiful singing voice. It was a lucid dream, but a few minutes after I finished, I realized in the dream itself that I had completely forgotten the music I had just composed. I'm not sure why it is so hard to remember original music from a dream, but it seems like other people have experienced this memory problem as well.