Glad you figured ut out!, I am learning some midi stuff myself, and the theory of relays is interesting, glad I could help even if just a little.
Most important to me is that you got it figured out, and posted results. People forget that when you get your project fix, or figured out to post how you did it, just think of all the people your answer might help. To me nothing worse, then when Im reading a forum post, and i see all my similar issues, and the last post is, never mind i figured it out, no schematic like you posted, or any hint! It would be cool, if you ever end up putting it on you tube or anywhere to post a link, id be interested in your finished project. Or feel free to do an article or example on my site rduino.com I have been very slow at posting to it. mostly because I do not document man of my projects!
HANKENSTIEN