In the interests of more screenshots, here's an example of what one can do in a real Lisp application. Full disclosure: all of the layers of software above glibc (sbcl, McCLIM and gsharp itself) have version numbers below 1.0 — so don't be too surprised that it doesn't display the second beam of the semiquavers...

Consider the engraving of a piece of music such as Dvořák's Humoresque. You know the one: ‘dum-de dum-de dum-de dum-de dum-de dum-de dum-de dum-de dum-de dum-de dum-de dum-de daaaaah’. Well, typing this in in a linear fashion is an absolute pain; the engraver must change the input state between each note, or must modify each note after placing it.

What are computers for? Well, one would hope that at least one could use them to automate repetitive tasks. Emacs, for one, has keyboard macros for just this. So, first enter the notes, then C-x ( ] . C-f [ [ C-f C-x ) defines a keyboard macro for turning crotchets into real rhythm, and C-x e executes it. Apply a liberal dash of barlines, and voilà! Kudos to Robert Strandh for a neat patch (and, let's face it, for writing most of gsharp and a fair bit of McCLIM in the first place). One could also imagine writing a specialized function to alter the input state in the desired fashion automatically; that wouldn't be hard either, I think; but this is already a good feature to have.