LilyPond 2.5.26 for Windows uses Verdana as the default font, but I want 
to use the serif and sans serifs Minion Pro and Myriad Pro. I've been 
getting away by hacking lines 355-356 of C:\Program 
Files\LilyPond\usr\share\lilypond\2.5.26\font.scm to read:

    (add-pango-fonts n 'roman "Minion Pro" factor)
    (add-pango-fonts n 'sans "Myriad Pro" factor)

But I don't want to have to do this. How can I declare the default roman 
and sans fonts in a document?

Thanks,
Basil