This has the Royal Theme in the top voice while the lower line is made into a canon. One note, however, about that lower line. The book, Godel, Escher, Bach plumbs this subject, making correlations between the mathematician, the artist, and the composer. This is a large area of research now, with much evidence pointing to the positive benefits of musical study. Not being a scientist I can only speak anecdotally about these matters, but as a music teacher I have no doubts.
Music lessons are definitely good for the brain.
Musical training develops memory and concentration, as well as auditory, temporal, sequential, and rhythmic skills. There have been many, many articles written on this subject in magazines as well as scientific journals. One excellent article is from the July 24,2000 issue of Newsweek magazine. Definitely worth getting to know. I'd like you to listen to and think about.