First, excuse me if I make spelling mistake (I'm French and my English isn't very good).
This is my problem : when in lilypond I use \< and \! to have crescendo, the crescendo is made with many little horizontal ligne. For exemple see here : http://www.cam.hi-ho.ne.jp/oishi/lilypond/crescendo.gif (that's a bit much...)
How can we wreathe crescendo ? Is it possible ? And if not, does lilypond will add this fonction in a next version ?