LilyPond is a music engraving program devoted to producing the highest-quality sheet music possible. Org-mode supports lilypond source code blocks that can generate music scores with optional auditing via MIDI. There are two modes available with ob-lilypond: basic-mode (default), and arrange-mode Which one you use depends on what you intend to do (type M-x org-babel-lilypond-toggle-arrange-mode to