No, this is now the latest template. That's what I'm using in all my books now, and it's coming from a more advanced project for writing music books http://orkestrix.org/
My goal was, if I could write about code and music at the same time, then making a build system for books would be easy. The above is the end result of that work. Enjoy.
I understand you don't want to use LilyPond because it is too complex, but you may want to know that LilyPond comes with a tool to convert from ABC to LilyPond (abc2ly). One could use it to write the music examples in ABC and have LilyPond typeset them. I'd consider using a setup like this to typeset the "final" version since LilyPond's typography is so nice.
My goal was, if I could write about code and music at the same time, then making a build system for books would be easy. The above is the end result of that work. Enjoy.