org-babel-lilypond export, automatic image trimming?

[James Harkins]

Any org-babel-lilypond users out there?

I've just managed successfully to get lilypond to compile a png from an org 
source block and include it in a beamer frame.

However, lilypond is generating a full-size A4 page, but these are very 
short examples and I'd like them to be trimmed automatically to include 
only the visible content. I realize I could set \paper variables inside the 
source block, but these are examples for beginners and I don't want to 
confuse them with any extra syntax. (The code will be visible as well, 
using ":exports both.")

"convert -trim" will remove empty white space, but the "music engraving 
by..." message at the bottom of the page is not empty white space, so it 
doesn't really help by itself. Again, including extra syntax in the lp 
source block would introduce syntax to the audience that I don't want to 
have to introduce at the very beginning.

Just wondering if anyone else had tackled this problem before. I can always 
take screenshots by hand, but I was hoping to have orgmode export handle it 
for me.

hjh