I am so glad to know that you like it Sigrid!
The score lines were laid in free hand and then “shaped” with a ruler and stylus. You can see how I use a stylus in early drawing layers here:
http://www.smartermarx.com/t/painting-video-using-a-stylus-in-early-painting-layers/129
And yes—there’s indeed a 42! Although it might be a little hard to see with this resolution. 