Some nits. Thanks for adding this! https://codereview.appspot.com/187140044/diff/20001/lily/separation-item.cc File lily/separation-item.cc (right): https://codereview.appspot.com/187140044/diff/20001/lily/separation-item.cc#n... lily/separation-item.cc:190: "Draws the @code{horizontal-sklines} of each @code{PaperColumn}," s/sklines/skylines/ https://codereview.appspot.com/187140044/diff/20001/lily/separation-item.cc#n... lily/separation-item.cc:191: " showing the shapes used to the minimum distances between" `used to'? This sentence looks weird... https://codereview.appspot.com/187140044/diff/20001/lily/separation-item.cc#n... lily/separation-item.cc:193: " before staves have been spaced on the page.") s/have been spaced/ have been spaced (vertically)/