Comment #17 on issue 2858 by [email protected]: Document \shape music function http://code.google.com/p/lilypond/issues/detail?id=2858
Issue 2873 has been committed. \single is not going to be interesting in connection with \shape since you can just apply the new form of \shape directly as a tweak. In a similar vein, there is no need for being able to specify the affected context for the override (like TabVoice.Slur) since Bottom will be fine for all the things that you would want to use \shape on.
In other words: I don't think that anything should be blocking _this_ issue any more.
