> What is the thing you (especially new users) like the least about LilyPond's documentation structure?
Insufficient explanation of the object model, the process model and the hierarchy of languages used and how they fit together. Example: Does anyone here really understand what a "voice" actually is? How about an "engraver"? (If so, I have many follow-up questions for you...)
At the root of the problem is that the documentation allows you to think that lilypond is a program to organize music. When it is really a program to organize grobs.