Global Font Change?

[Christopher Meredith]

I've done a lot of searching but am still having some trouble.
Basically, I want to globally change the text render font from Century
Schoolbook to a different serif font. The font I want to use is a
system-installed OTF font and it is working, except I can't get
italics to work. I have tried the following methods:

1. Setting make-pango-font-tree in the \paper section of the .ly file
2. Changing font.scm
3. Overriding the font at every occurrence

In each of these instances, the new font is rendered, except for
italics. Is there something I am forgetting? Thanks.